I have never though, asked for separate checks or had anyone else ask for separate checks, anyplace. It's a weird idea to me - like, you can't just look at the check?
NYC.
We run in very different circles & restaurants. I've been on numerous outings where we ask for separate checks right up front or the
waiter always asks us if we want separate checks (if he can do it that way on one table,) or should he put everything on one check.
If it's on one check, generally we will all look at the check and pay our share. If we have ordered a round of appetizers for everyone to share, we divide that and add it onto what our amount of that will be.
There have been a few times where one person will grab the check and say we all evenly split it. But, THAT person is usually one who has ordered several alcoholic drinks and/or appetizers.
I and a couple other people do not drink alcohol. I don't even drink sugary drinks, (I'm pre-diabetic,) so I drink water and I will NOT pay for another's booze tab.
Once, one friend only ordered a $10 entree. When the bill arrived, one guy divided up the bill and told everyone they owe $25. Sorry! But, I fought for my friend who was in shock and rather timid. She should NOT be paying one and a half times what she bought to cover other people's food/alcohol choices. A couple other people spoke up for her, too. We actually live
in NYC, where we speak our mind. We ended up paying our own share, much to the guy's irritation, who had ordered a LOT.
Paying our own share has always saved someone from having hard feelings at the end of the evening or a similar disagreement.
I have noticed that people who live on the outskirts of the city, or in other places where social status is very important, may want to evenly split the check. I suspect it has more to do with hiding the fact that not everyone at the table makes the same amount of money. Let's gloss it over, and pretend everyone is at the same monetary level. "We won't embarrass Susie for only having a part-time receptionist job. She will pay what everyone else is paying." Of course, the ones that this benefits the most are the one's who ordered the most. Which they do
every single time they go out. Those poseurs get to eat at everyone else's expense and pretend they have more money than they have.