There is a reason why people moved away from distorted text based captcha. We are basically at the point where computers are better at them then humans.
However a surprising amount of text based captchas can be solved in a few line shell script of, using imagemagik to convert to greyscale, dilate and undilate, then pass to teserract
However there are also sites like https://2captcha.net , so really captchas are more like putting a small min amount of effort.
https://www.usenix.org/system/files/conference/woot14/woot14... is a paper on the subject i think is really interesting
However a surprising amount of text based captchas can be solved in a few line shell script of, using imagemagik to convert to greyscale, dilate and undilate, then pass to teserract
However there are also sites like https://2captcha.net , so really captchas are more like putting a small min amount of effort.