In the future bots will have CAPTCHAs to keep humans out of their communities

You have 50 milliseconds..

Some fifteen year old nerd: "I got this"

Could you use another bot to solve that bot's test?

We already have the reverse, where automated spam tools outsource to humans to beat the captchas: https://www.nytimes.com/2010/04/26/technology/26captcha.html

They would have to make a captcha that only a select group of bots can solve