Totally get that. You've already got a great way to identify the meaningful problems - it doesn't come out of thin air, but out of your experience working with people, clients, etc...
That's the point of Step 1: Wanna know what problems a client is facing? Ask. If you don't ask, you'll never know what solution to build.
Ah - well you're directly tapped into the problems they all have, even if they see you as just a tool. You're working with so many different businesses that you have a bigger sample size. What's a recurring problem? How can you solve it at scale? Not saying it's easy at all, but you probably have an advantage over someone who just works for a single company.
We just started by solving our own problems as a marketing agency. Eventually we found one that enough other people had (through this testing process).
That's the point of Step 1: Wanna know what problems a client is facing? Ask. If you don't ask, you'll never know what solution to build.
The quitting of the job can come later :)