Useful to be precise here: "bots" is a catch all term that people use to describe low effort, uninteresting or otherwise off-topic content.
However, a "bot" is traditionally thought of as a programmatic account, i.e. controlled by a script or software. e.g. bot net
When people on Farcaster refer to "bots" they are more often referring to actual people using a mobile device (with the aid of translation tools and ChatGPT) who post uninteresting content (from their pov).
They are casting and replying in hopes of appearing to be a "real account" because they have learned that turns into a future economic reward in crypto. Recent tipping meta has increased the expected value of these accounts.
It's possible to algorithmically label these accounts, but then you create a "shadowban" meta. So you massively increase the number of support messages and complaints. This was the state of the world before priority mode.
We're going to keep iterating here, but our pov is:
1. Priority mode works pretty well out of the box
2. We need to offer ways for actual interesting accounts to break through
3. We'll likely bring back some version of spam labeling since priority mode has created it's own set of customer support complaints.
"Why don't you just use onchain signals?"
a. Based on our waitlist last year of 300K sign ups, "bots" have plenty of Ethereum addresses with assets.
b. Most new users don't want to connect an address during sign up (friction, doesn't work well on mobile). So you'll miss out of on good accounts.
c. Active onchain presence != you regularly post interesting content. There are some people of course, but plenty of examples otherwise.
Appendix
1. Meta estimates that 10% of users on their products are potentially bots. 300 million accounts. Says it's hard a problem to solve (even for them).
2. web2 social networks can delete accounts. Farcaster cannot. Warpcast can label as spam / reduce visibility.
"Just use proof-of-humanity"
See the point about real human using a mobile device. That doesn't solve the problem.
"Just use another social network signal"
Plenty of "bot" accounts on Twitter, also now on GitHub because of Starknet.