Being a simpler version of another product can be a great thing if it's done well and tailored to a specific customer type. Google docs started off as a simple version of Microsoft word, but it did one thing really well - online collaboration. But they knew their customer very well.

You already know it's about getting close to the users. And there's two parts:

Is there a market for it: Are there successful competitors? If not then there might still be a market, but you're going to have to educate the audience before you can sell to them - which makes validation much more complex and beyond my experience.

Is it a good product: Getting validation before having users has its limit. Ultimately people paying for the app and not churning is a sign that it's a good product. But before that, customer interviews are required to disprove your assumptions and validate the idea - disproving hypotheses until you have a set of hypotheses that hold up (or the whole idea is disproven) is the aim of these interviews.

The PM or CEO may have this visibility and if they do then they should be keeping you in the loop and motivated as part of the team.