>>38951557Generation 2->3 was a technical problem. Pokemon data was stored way too differently between them, and transferring would require using a link cable from a Gameboy to a Gameboy Advance, which I'm pretty sure would have some kind of issues. Nevertheless, every Pokemon in the previous generations was obtainable in generation 3 from a generation 3 game.
The problem here isn't that we can't transfer Pokemon over. We can! There are some Pokemon in the Galar region that were obtainable in generation 3, so it should theoretically be possible to transfer a Pokemon all the way up to generation 8 through Pokemon Bank into Pokemon Home. But we can't do that with all species of Pokemon because not all species are programmed into generation 8. This is a different problem that we haven't had before.