Guys, stop the "commuter wars" here.

There are pluses & minuses to every area one recommended to live in. Ultimately, it comes down to the trade-offs the OP's son will find acceptable and can live with. Some will be bottom line, "No way" doing that again. Others will be acceptable. It will be trial and error the first few years to find that out.
OP, I also suggest that your son NOT sign for more than a 1 year lease or roommate situation. And definitely not buy a place to live. He may decide to live somewhere else. A longer lease, while less expensive monthly, ties him into a place that ultimately may not be right for him. Breaking a lease may be more expensive.
The majority of his friends may end up in a different area. He may find he really loves one neighborhood more than others.
NO one mentioned when the commute gets messed up. Google for photos of when people are packed in and stuck in Penn Station or the Path Train or Grand Central Station for HOURS because the trains are messed up due to breakdowns. He HAS to get to work, how WILL he do that on those days? Uber? How much will that cost? A train derailment means that train line may be down for a couple days. Then there's the "snow storms" in the NYC area. A "snow storm" here is about 4
INCHES. People in Buffalo, NY, Chicago, Minnesota, the Dakotas will laugh at that. But, in NYC, a 4 INCH snow storm/Nor'easter can mess up the commute for hours or a full day, even living in one of the 5 boroughs. Is he willing to sometimes have to leave an extra hour or two earlier to make it to work on time?
Also, when one lives by a train schedule, they are TIED to a train schedule. If he works late, there will be less trains than at rush hour. When a bunch of us go out at night, the people who have to take a train have to leave by a certain time. Missing it may mean another one may not be for another hour or more. Then there is having to get up an hour or two even earlier than normal when they know there will be weather delays. So, when do they sleep?
As for driving in, in addition to cost of insurance, the closer one lives, the higher the insurance. DS is under 25, so insurance will be even higher than that. Gas is more expensive closer to the city, and some of the tolls just went up
yesterday. Expect all of them to keep rising as they make up for what they lost during COVID. Crossing the George Washington Bridge or Lincoln Tunnel is about $16/day. Then there is the expense of parking in the city if he doesn't work in a building that includes it. Even if he only does that occasionally, down in the financial district, a day parking could be probably $75+.
Yet, living within the 5 boroughs isn't a bowl of cherries either. It's more expensive in every way possible.
Every expense adds up. E.V.E.R.Y. Sure, he may be making a great salary, but every expense adds up in a city where everything is more expensive. Real estate is more expensive. A doorman building will be in a better neighborhood.
The better the neighborhood, the more expensive the foods in the supermarkets - which really aren't that big. So, there is less of a selection of items. There are rarely off-brands or cheaper store brands. A can of corn at
Walmart is about 59¢ nationally. Walmart is banned in NYC purposely, as they would kill all the mom & pop stores. A can of corn or veggies in Mid-town Manhattan, where I live, is $2. On sale, it's $1.59. Times that by six cans and it's $6 more than nationally. Times that by buying six cans of, say, chick peas too, and it's another extra $6. Times that by everything in NYC and you start getting the idea of the cost of living here.
There is really no such thing as the "dollar menu" at McDonalds or Wendy's. Last time I went in, it was $1.59 for a typical $1 item. And pretty much only the kids juice box is left on that dollar menu. Those national Applebees commercials, where I see entree or appetizer specials for aout $8? Here, it's about $12.99. Last time I went to a movie, pre-COVID, it was $16-$18 for one ticket. That was not including the popcorn or drinks. Bundled cable and Internet, after the first introductory year, is about $200/mo, with no premium channels. A good gym is another $200/mo. Monthly unlimited subway metrocard is $127. Phone would be another expense. If DS doesn't have a doorman, he won't be able to have packages delivered at home. The porch pirates would snatch the packages even before the UPS guy started the truck back up. If DS has packages delivered to work, yet has to hire an Uber to take a lot of packages home, that's another expense. So much for free shipping.
I live in Manhattan because I moved in decades ago when I went to NYU, when Hell's Kitchen/Times Square was quite a seedy, dangerous neighborhood. Back then, one took their lives into their hands when they walked over to my avenue.

But, I thought I was invincible back then. The NYC Guardian Angels street vigilante, safety patrol organization started and first headquartered in my neighborhood, as it was so dangerous here. I got an apartment at a great price, under rent control laws and the rent has barely gone up much since. So, it's affordable for me. Otherwise I couldn't live here. Yet, my landlord tried to manufacture ways to evict me TWICE. I had to hire a tenant attorney both times to fight him. My landlord didn't think I'd fight back or would know the law. He was hoping to get me out as he could jack up the price of this place to whatever is the current price. He's done it to other tenants.
Subways come to a crawl at night. After midnight, they run about once an hour or so. If one has to take a connecting train, and they don't line up, as they usually won't at that time, one can be waiting on the platform for the first train for an hour, having just missed a train. Then waiting close to an hour for the connecting train. I used to teach at night in Brooklyn. I'd stay late to do my own artwork. But, a subway ride that is 40 minutes during the day became a 2.5 hour ride home if I missed the train right before midnight.
Now, due to COVID, the trains are shut down completely for a few hours overnite, to clean the trains.
Subway ridership is now down by 70%, whereas crime is down in the city by only 50%. People stayed off at first due to COVID, but now due to the massive amount of crimes and
types of horrific attacks happening now. That one was about the NINETH subway platform push in several
months. When I first moved to NYC, during the "Death Wish" era - the amount of uncontrolled crime which inspired the Charles Bronson series of movies thus named, there was one subway platform push maybe every 2-3
years. The NYC Guardian Angels and NYPD are back to patrolling the subways. But there are not enough of them for every subway or platform. Plus, the attack I linked to, there
were two officers on the platform. They only stopped the attacker
after the push. The attacker was only charged with
attempted murder, as the person she pushed stumbled
downward for a split second before pitching forward into the side of the train. That stumble saved the person's life.
Just
yesterday, a woman in Brooklyn was grabbed by the arm and was twice nearly pulled off the platform, onto the tracks. Luckily bystanders stopped the guy, But, he got away before police arrived. So, he's free to try again. Men have been pushed and killed onto the tracks too. Many people have moved out of NYC in the past year as crime is on the rise here, both above and below ground with shooting and stabbings. It's NOT just in the usually more dangerous neighborhoods. This is the most dangerous NYC has ever been during the decades I've been here.
Again, there are many factors which may factor into where DS decides is right or acceptable for him.