Problem discovery is not very hard, and product managers who spend a lot of time on it neglect solution discovery, the real work they are paid for.

Yes, you obviously need to make sure you understand the problem, who you're solving it for, and what the definition of success is. But honestly, that's not very hard. It's not very hard. And if you spend a lot of time on that, you're not going to do the real part you're paid for, which is solution discovery.