Off-ramping to fiat would be criminalised and pursued beyond the wildest dreams of La Liga/Cloudflare. A gambling site you can't withdraw your winnings from is of no interest to anyone.

You can block the web user interface and effectively block Polymarket for 99.9% of users. No ban is ever 100% effective.

Prison bars are an unpatched DoS vulnerability that affects all blockchains.

https://xkcd.com/538/