The account that MicroRNA mentioned had averaged over 21.5 hours per day for four months straight. Sure, there’s a technical possibility that this is a single parent/guardian and their single minor child/ward, splitting that amount of hours between them. However, it’s a damned sight more likely that it’s multiple adults account-sharing and/or botting. That’s why the high play time isn’t the cause for a ban, it’s cause for investigation into whether it should be banned.
You should check the leaderboards though. The top slots are full of accounts like this, where they average those sorts of hours, for an entire season, for multiple seasons in a row. There sure does seem to be a lot of single parents / children doing this, if that’s the case…