That's not how copyright infringement works. Great, you've stopped committing new infringements, but there's still a legal case over the previous infringements, for which you still need to provide appropriate remedy.

If the remedy for copyright infringement were just "oh, we got caught, guess we'll stop now", that would provide substantial incentive for people to violate licenses as long as they hoped they wouldn't get caught. The remedy for such violations needs to be substantial enough that it's not profitable to temporarily get away with.

>> Nothing is forcing them to do that.

If you use AGPLv3-licensed code in your codebase, you are agreeing to the terms of the license.

Practically all corporate legal teams for companies that creates software will strictly prohibit the use of AGPLv3-licensed software, if not all GPL-based licenses.