Google is working on that with reCAPTCHA v3. It takes away the challenge part and just works on assigning a score to actions and then using that score to determine if it is a bot or not. I'm not totally convinced it will be successful as I imagine the bot writers will just work out action the site administrator has assigned as good and get the bot to do them. But it does seem at least the direction of travel is away from direct challenge captchas which don't stop bots anyway.