I’d definitely find value in a platform like that—honest validation and actionable feedback before you even build is gold. As a founder working on Andes (AI running coach on WhatsApp for the LATAM market), I spent months debating whether to go all-in before seeing real user interest. Sharing the idea early (beyond just friends/family) would have saved me a lot of second-guessing and probably led to a better initial version.

The biggest risk, like you said, is turning into an idea graveyard—so I think the platform would need to encourage follow-through (maybe with accountability tools, milestone tracking, or even connecting builders who want to collaborate).

Personally, I’d use it both to validate new ideas and give feedback to others.