To answer the OPs question. Hotels in Vegas still make a lot of their money with guests gambling. Low hotel rates don't necessarily mean low quality. That said $25 for Vegas, today, is a little suspect.
Even pre-covid Orlando had a surplus of hotel rooms. Hotels can renovate, keep their properties fresh and charge a reasonable (profitable) rate. The Rosen hotels are good examples. Hotels in Disney Springs are generally good. Lower category Marriott and Hyatt hotels are generally OK. There are some good deals in Flamingo Springs.
Low rated hotels (low priced) attract prostitutes, drug deals and low income housing. You're looking at rooms with mold and mildew. Bugs. Cigarette burns. AC filters that are filthy. Towels and sheets with holes. Towels that are so thread bare they won't dry you.
I stayed in a Knights Inn, maybe 30 years ago. Included continental breakfast was so bad I grabbed coffee and danish at 7-11 on the way to the parks. I was fooled by a good
AAA rating and was staying by myself. I was meeting family, rope drop to park close (many nights pleasure island) I didn't bother trying to find a better hotel. The on property Disney hotels were all booked. It was around $40. The deadbolt didn't even work.
JMO, around $100 /night is the minimum rate to expect a decent room. A few dollars less if you have a promotional rate or slow season. Anything you can readily get for under $80 requires a lot of research. Under $20 a night, worse then you could possibly imagine.
Really sketchy hotels in Orlando seem to be able to get 3* ratings. Anything below 3.5 * requires research. Look at RECENT reviews on trip advisor, yelp etc.
JMO, the only reason to books some of the hotels. Sometimes you'll get package price for air and hotel which is much cheaper then just air. The included hotels are the kind listed in the OP. Consider it an air only booking and don't even think of checking into the hotel.
edited to add with the air hotel package deals...a throwaway room is frequently a better deal the upgrading the hotel in the package.