Indoor smoking, 110F weather, and universally crappy, over-priced food.
"good restaurants": (1) lots of top-tier cooks go there because money and it's cheap because Vegas, or (2) lots of off-strip places with good chefs trying to make it big.
"crappy, overpriced food": (1) Wolfgang Puck etc, or (2) Even off-strip food is bad and expensive because they can't afford water.
So in reality which is it?
However, there are also some of the best buffets in the world there (if you're into that). There are also some awesome high-end restaurants: https://www.tripsavvy.com/michelin-guide-rated-restaurants-l...
Because Vegas is a massive tourist destination where you are guaranteed to have a deep market of people eating out every day of the week, it attracts tons of restaurants so you do need to do a little research. Picking a random one will likely get you overpriced 'meh'.
We've gone off the strip for sushi, Korean bbq, Thai, and Ethiopian and had good luck; I don't know enough about greater Las Vegas to judge it. But the strip is bad.