American here. Really it’s about context. On busses is can be polite to thank the driver when exiting. Depending on the barber saying hello to everyone might be normal too. But no I don’t think I’ve ever walked into a dentists office and been like’ hi! Everybody!” It’s more a walk in tell someone you’re here and sit on your phone until called.
Not to pat ourselves on the back too much but right now it’s mainly the Reddit power users that are here. The normies are wondering why interesting as fuck was flooded with porn as of last night.