Many of us are well aware that there are ways around captchas. That's not the point, nor are you disappointing me with that 'news' (although that you would spend time trying to work around a captcha is dissapointing, because it means you are either wasting your time, or working towards nefarious ends)
Watir is designed as a test tool. For people doing legitimate testing, there is no need to meatbot your way around a captcha. You do limited manual testing as needed in your live environment to validate the captcha is configured correctly and working. In your test environment it is coded around, turned off, or hits a special stub that uses a predictable response (or embeds the expected value in the HTML). Just as you would turn off any online advertising, website metrics, tracking pixels, and other code that is typically 3rd party and has no value (or negative value) running in a test environment. That's generally easier, cheaper, and does not serve to support a service that exists only to facilitate spamming.
So what purpose is there to determining if watir can be used to source a captcha to a meatbot? I don't see this as a criteria for a legitimate tester, but rather for someone who is trying to use watir as a tool to bypass captcha's and post spam to websites that don't want it posted there. and if that is your purpose, you will find zero support for it here, go abuse someone elses tool (which given that the message is coming from the webdriver side, will not likely be based on webdriver) Otherwise I'm here to tell you that's a poor criteria for selecting a test tool since there are better ways for testers to get around captcha's running in a test environment.