Someone making an argument like that clearly does not understand the situation. Just 4 years ago, a robots.txt was enough to keep most bots away, and hosting personal git on the web required very little resources. With AI companies actively profiting off stealing everything, a robots.txt doesn't mean anything. Now, even a relatively small git web host takes an insane amount of resources. I'd know - I host a Forgejo instance. Caching doesn't matter, because diffs berween two random commits are likely unique. Ratelimiting doesn't matter, they will use different IP (ranges) and user agents. It would also heavily impact actual users "because the site is busy".

A proof-of-work solution like Anubis is the best we have currently. The least possible impact to end users, while keeping most (if not all) AI scrapers off the site.