This is a problem for short fiction submissions and it's not just going to go away. The link goes into details, but this is a graph of submission bans since 2019. Plagiarism and bot-written spam.
http://neil-clarke.com/a-concerning-trend/
A Concerning Trend – Neil Clarke

@clarkesworld Is shadow banning an option? Maybe letting the cheaters submit, but internally throwing to the bin everything they send from specific users, IP addresses, etc.

If they don't have feedback, it would be less likely for them to change strategies, like creating new users.

@doublemauler Given what I know about this crop, shadow banning and honeypots wouldn't be very effective. I've used these techniques in other systems I've developed.