You can actually. You just can't tp them to another dimension or another minecraft world but it could tp them to a faraway spot so it feels like a different world.
While that can 'simulate' that feeling, there is no actuality about it. As far as technicalities go, you'd be in "world_1" the entire time, which is not necessarily what the OP wants. If "world_2" has to use gamerules or options different than "world_1", then you cannot simply teleport a player to a different location in the same world. I assume he's talking in terms of plugins that allow players to switch between worlds, and wanted a vanilla solution to that.