Your description is highly likely to be inaccurate. There's tons of people with illegal Pokémon that are not banned.
Ignoring what a random Poketuber said (cause they typically contain misleading information or they don't follow up when changes occur, or have reasons to lie in their video etc etc), it appears that the bans are targeted to (1) sellers'/distributors' HOME account, as well as HOME accounts of anyone who interacted with those sellers'/distributors' accounts, AND (2) any account that has illegal mons, that also fulfill condition (1).
At present, if you have illegals but don't fulfill condition (1), then you probably won't get banned.
[At least, that is what I've seen as well as heard.]
Note: the situation can and likely will change.
Edit: There's presently some reports, that says some bans seem to indicate (3) transferring Gen 8 mons from Bank into HOME, without fulfilling condition (1). However, more of such cases will need to come in, before we can rule it as a confirmed scenario.