Sure, but it seems easier to defeat than captchas, especially for a big opponent like a state, which can possibly allocate enough computing power to make the difficulty target too high for regular users

Whereas with captchas, the government need to pay real people to fill them, which doesn’t scale

Edit: I read the paper (https://gitlab.torproject.org/tpo/core/torspec/-/blob/main/p...) and I understand what you meant. This is not meant to replace captchas but to automatically discard low profile attacks. Nice.