I assume that the gitea instance itself was being hit directly, which would make sense. It has a whole rendering stack that has to reach out to a database, get data, render the actual webpage through a template....etc

It's a massive amount of work compared to serving up static files from say Nginx or Caddy. You can stick one of these in front of your servers, and cache http responses (to some degree anyways, that depends on gitea)

Benchmarks like this show what kind of throughput you can expect on say a 4 core VM just serving up cached files: https://blog.tjll.net/reverse-proxy-hot-dog-eating-contest-caddy-vs-nginx/#10-000-clients

90-400MB/s derived from the stats here on 4 cores. Enough to saturate a 3Gb/s connection. And caching intentionally polluted sites is crazy easy since you don't care if it's stale or not. Put a cloudflair cache on front of it and even easier.

You could dedicate an old Ryzen CPU (Say a 2700x) box to a proxy, and another RAM heavy device for the servers, and saturate 6Gb/s with thousands and thousands of various software instances that feed polluted data.

Hell, if someone made it a deployable utility..... Oof just have self hosters dedicate a VM to shitting on LLM crawlers, make it a party.