Emailed out the latest edition of Unvalidated Ideas, one of the ideas in there I think is great for the world and your bank account:
Browsing sites with text that's nearly the same color as the background is the worst. Now imagine having a more serious disability and being completely unable to read the site, or receiving completely nonsensical information from your screen reader.
Getting Accessibility ("a11y") right is important to a lot of people and a lot of companies. Aside from the usual capitalist reasons, there are many governments and organizations that make it their job to help those with disabilities, but it's really difficult to pull off -- any new code could introduce a lapse in accessibility!
Your mission, if you choose to accept it, is to help companies stay on top of their accessibility, and ensure it never dips below a certain level. There is great software out there for doing this already (Pa11y and axe, for example), but for large organizations it's often harder than you'd think to make sure they're run on every public part of their websites.
It's important enough that there's a Digital.gov site dedicated to it. Other countries like the UK have too. It's obviously a trend, so follow that trend.
Take this idea to the next level by becoming a Trusted Tester (USA), then chase similar status in every country you can. There's no reason you can't be a trusted, consistent expert in the US, EU, and every other nation that has made this a priority. The more certifications and experience you can build into your solution the easier it will be for global multinational corporations to trust your solution.
NOTE This idea could be a feature of a larger web testing platform (ex. a lot of competition out there), so keep in mind that some competition could be much larger than you are. In the end, if you execute well enough they'll just be potential acquirers, rather than competition!
Unfortunately most of my ideas aren't this helpful to others but maybe subscribe to the newsletter anyway.