Besides finding better ways to positively recognize bots, we also need to invent ways that make it quicker to realize "false alarm, this user is actually legit".
For example, users should have an option to pin posts and comments to their profile, and I suggest to provide at least two different 'tabs' for this in the public profile: One tab just for the usual "posts and comments you would like the world to see", but another tab for "some recent, complex interactions between you and other (established) users that in your eyes prove quite well you're not a bot". The purpose is simply to save others, worried that you could be a bot, some time of going through your posts in search of signs for humanity. Yes, this can be gamed to some degree (what can't?). However, at a technical level, the feature is little more than a copy of the "pin" feature that would be very nice to have anyways, so we can get an appreciable improvement in our ability to tell users from bots for very little programming effort.