Furthermore the bots’ solving times are significantly lower in all cases, except reCAPTCHA, where human solving time of 18 seconds is nearly similar to the bots’ time of 17.5 seconds.
Due to this solving time captchas still provide an easy method how to reduce spammy request count. Also kind of doubt it is super easy to create your own setup that would bypass captchas so everyone could do this, but there probably are 3rd party services exactly for this.