Most open source text captchas have ML/DL or OpenCV OCR solutions and more advanced captchas like gcaptcha/hcaptcha you can send to a solver farm like 2captcha. The cost for the farm solutions is pretty cheap.
Still pretty expensive if you wanted to do every single Valid CC #, though.
Wasn't something I mentioned earlier but using the reCAPTCHA audio is also another solution for gcap. I haven't ever used it personally but always seemed like a cool idea.
It’s also very satisfying to know I’m not an unpaid mechanical Turk for google anymore and that it’s a machine solving another machine’s challenge.