The game is shifting to a better ideal: how do you design a service knowing that any user/request might be automated?

Especially in place of the historical, easy solution/hack where you have some sort of gate that, once passed, puts the user in some trusted low-scrutiny tier, like a forum's registration page.

It's a similar question to designing a system so that it's resilient to account take-overs. (i.e. The user was a trusted human until now, and now it's a spammer)

Example: on a forum, run new posts through an LLM to classify it as spam which is a magic solution we always wish we had (remember akismet?) but was too rudimentary.