Simply make Google and Apple take it down from their app stores, and it would be de facto banned for 95+% of users.

America has a Great Firewall, it's called AppleMobileFileIntegrity.kext[0]. The TikTok ban relied heavily on the fact that a social network practically needs to have a mobile app and thus prohibited them from having it. It was less of a "ban TikTok" bill and more of a "government gets to kick apps off the App Store" bill.

Yes, you could use TikTok on the web; but... have you ever tried using TikTok's web interface? It's an absolute joke. And on the other end, shipping a webapp subjects you to all sorts of consumer-friendly technical interference like ad blockers and de-cluttering that is intended to make the social network serve the user and not itself.

[0] On Android, TikTok did ship an APK to evade being kicked off Google Play; but that's only slightly more effective than telling people to go run AltStore on a Mac or PC to dev-sign a TikTok IPA that will be missing half the features because Apple doesn't allow certain permissions to be provisioned on free dev accounts.

But that would be a great firewall if they applied it as broadly as suggested (to all services that dont transfer majority ownership to EU).