Proof of work is what those modern captchas tend to do I believe. Not useful to stop creating accounts and such, but very effective to stop crawlers.

Have the same problem at work, and Cloudflare does jack shit about it. Half that traffic uses user agents that have no chance to even support TLS1.3, I see some IE5, IE6, Opera with their old Presto engine, I've even seen Netscape. Complete and utter bullshit. At this point if you're not on an allow list of known common user agents or logged in, you get a PoW captcha.