I was really tempted to reply looks decilious, but it might not be as funny as I meant it to be.
I completely agree something needs to be done. Could the system not be configured not to allow Bots at all? I know nobody likes seeing lots of captcha prompts, but you really want real comments, not junk.
Not sure what the answer is, but it's definitely a problem.
Unfortunately even captcha prompts aren't the way forward..
They will get bypassed through services like deathbycaptcha/2captcha and just make it hard on the genuine users.
If bot owners obtained no profit from spamming comments then they would stop (or really improve their system to the point it looks legit)
A mass flagging operation/blacklist would work but it could end up harming an honest user..
Honestly I think there needs to be a way for a communal suspension (under a certain reputation threshold of sorts)