Option to change what version the world will be in

An Option when you create a world that can change the version of the world you want to make, Example: I want create a 1.17 world in 1.21. This option would be amazing because lots of people of console want to change versions but can't, and other people don't like the newer updates and prefer the old. This would also bring back old players. And also with this option you could also update the world form 1.17 to 1.18 so that when you create the world it won't be stuck on 1.17 forever. People have found many crazy seeds before cave and cliffs and now the cave and cliffs update completely rehauled world generation.