Just to add to the two negative replies, I find Anubis to be the only system that doesn't ever get in the way. My browsers have Javascript enabled and, so far, it never took more than a fraction of a second to complete the checks

Every other system I've run into has constant false positives, e.g. Google captchas will sometimes say I've failed and make me do the hardest level (if it wasn't giving me that already), Cloudflare regularly thinks I'm a bot, Codeberg blocked me before, Github signup captchas used to take ~15 minutes to complete and then still said "well you failed, try again", Github's general rate limiting has false positives (some days I browse a lot, other days little, and on the little days it'll sometimes go "slow down" with no recourse whatsoever, you're just blocked for an indeterminate amount of time), OpenStreetMap blocks my browser at work because I'm using Firefox ESR instead of latest stable and it finds that user agent string to be implausible, whatever the german railway operator uses since a few days is triggering on me constantly, etc.,

etc.,

etc. Constant blocks everywhere.

With Anubis, my understanding is that you do the proof of work (with whatever implementation you like, it doesn't have to be the Javascript one that they provide) and you can move on without ever doing any task yourself. The power consumption is a shame, but so long as attackers aren't even doing this much, the couple Joules it takes doesn't seem to be an issue

Of course, the attackers will evolve, but for now...