That argument also works against anubis. Why bother forcing clients to solve a PoW challenge, when you're fighting a bunch of unsophisticated attackers that will be deterred by a javascript challenge that requires them to solve `result = x + y`?

Point is, you get problems because of something like this, you try either approach. And when that stops working (because eventually it will), you add something else. Some work better against some actors, but also feels like it never ends, so slowly you add more things. I don't think Anubis is uniquely able to stop that particular type of annoyance, it's just one of the tools you can see if it helps. If you want to try something else before, makes a lot of sense to do so.

This is why there's the meta refresh challenge as an option: https://anubis.techaro.lol/docs/admin/configuration/challeng...

Turns out that in practice there's some bots that implement support for this but not JavaScript.

Caution: Techaro is very hostile to this line of thinking. He believes the PoW is essential. And that's fine - different projects use different approaches, like go-away and dogwaf.