Hopping from place to place and seeing tourist sites can be fun and relaxing, but it's ultimately also pretty meaningless. This was drawn in sharp contrast for me because I was living in a famous tourist area (Kyoto), and I routinely saw the vast differences between the way tourists experience the area, and the way locals do. There's a very established tourist route, and it has almost no overlap (other than commercial) with the authentic life of the city. Tourists arrive, see the station, visit a few of the "mass-market" temples and shrines, then they leave. Even the folks who have "authentic experiences" are more-or-less following well-trodden pathways.
It's hard, because I now find it difficult to travel to places where I don't have a deeper purpose for being there. Simply seeing something pretty is no longer enough. But I also recognize that this is, almost by definition, impossible for everyone to do. I like travel too, but I'm quite conflicted now.
Most forms of mass-market tourism are essentially no different from Disney World, but with worse environmental impact. They're cancerous, and unless tightly regulated, will destroy the very places they promote. At least Disney World was built in a swamp!
As for environmental impact, I think there is certainly an unfortunate factor of social perception making people fly half way around the world to Bali and destroy the local ecology in the process because Bali is supposed to be this enviable getaway place. But there's such a thing as a place being overrated, and if you arrive with high expectations, there's surely going to be a disappointment (even if you don't want to admit it). At some point, a beach is a beach. Coronado beach - just a hop away for me - is just as relaxing to me as Frasier island in middle-of-nowhere Australia.
If you're looking for unusual travel experiences with minimal ecological footprint, something that I've found nice (at least for major hubs in north america) is the atlas obscura city guides. Many spots there aren't even on maps (let alone touristic ones), and can't possibly take your whole day, so they're a great excuse to really go off the beaten path.