You cant really cache the dynamic content produced by the forges like Gitlab and, say, web forums like phpbb. So it means every request gets through the slow path. Media/JS is of course cached on the edge, so it's not an issue.
Even when the amount of AI requests isnt that high - generally it's in hundreds per second tops for our services combined - that's still a load that causes issues for legitimate users/developers. We've seen it grow from somewhat reasonable to pretty much being 99% of responses we serve.
Can it be solved by throwing more hardware at the problem? Sure. But it's not sustainable, and the reasonable approach in our case is to filter off the parasitic traffic.
I'm currently working on getting the Trixie packages uploaded. It'll be there this week.
As you've said Debian 13 was released 4 days ago - it takes some time to spin up the infrastructure for a new OS (and we've been busy with other tasks, like getting nginx-acme and 1.29.1 out).
Our documentation and a main website are not fronted by this protection, so they're still accessible for the scrapers.