I'm on AWS and use their WAF service to do some rudimentary bot blocking, but CDNs (their Cloudflare equivalent, Cloudfront) have been too expensive in the past and the bot control mechanisms they offer have too many false positives. Perhaps I should check it out again.
Part of the problem is the economics of it -- I've chosen to self-fund a high traffic site without ads, and that's on me. But it was possible to do this just a few years ago.