I think that the general way of life in other places is attractive for many (not driving everywhere for example, guns, easy access to healthcare, fresher food, more relaxed culture, less focus on consumerism) & the ability to be near more structural beauty. The US is pretty ugly in many cities imo
I second London for ease of travel back home. We moved abroad with the intention of going back home regularly… but it’s just too much time and energy to want to do it often (Greece to west coast). If you like warm weather I’d also consider some Caribbean islands. I lived on one (that absolutely does not fit your other criteria) and there was a small lgbtq culture in the locals, and I had some same sex hookups with other expats- so they aren’t as backwards as ppl make them out to seem.