>>37077522It's because it's very easy to make any pokemon "look legit" as long as you are careful, or are not actively trying to fuck something up.
And as far as save manipulations go...think of it this way.
Pokemon has to cater to an audience that isn't always connected. The save data for pokemon is constantly changing for every player. If I connect to the servers, disconnect, play the game normally, then reconnect, then of course I'm uploading a different save state than last time. Offline trades will change my save state too. And they can't ban anyone for changing save states between connectivity, cause it's something that can happen legitimately.
Honestly, that's probably also the reason they don't offer cloud saves for the let's go games. Between offline trading, online trading, go-integration trading....sounds like a nightmare to keep track of.