Except competitive pokemon has always been about the strategy involved in battle, not ones ability to waste dozens of hours breeding for a competitively viable mon. Functionally, there is absolutely 0 difference in battle between a mon generated through cheating (so long as it is something that can still exist in game) and one that is bred using in game mechanics. If you lost to such a team, you would have lost regardless of whether or not the mons were genned as your opponent was simply able to out strategize you.if you can't win through your own skills and merits, what's the fucking point of entering a contest if you're just going to lie and cheat your way through everything?
This sort of attitude that you need to breed all of your pokemon in game to be a legitimate player is nothing more than gate keeping in my eyes. People would much rather be spending time learning and testing strategies than spending mindless hours grinding just to get a single mon for a single build. It would be like if chess required you to fulfill some overly long, mindless task just so you can have access to a single bishop piece.
If Pokemon Home included a Showdown like mode, where you could generate pokemon (albeit, not transfer them to other games) and test them out in battle against other players, and they started using this for VGC, it would unironically be the best thing to happen to the series.