My validation strategy before building any tool: buy a keyword rich domain and launch a simple landing page.
I watch Google Search Console. If impressions and clicks start coming in organically the demand is proven. Then and only then do I build the actual tool.
No waitlists. No surveys. Just real search intent telling me people want this.
It's saved me from building things nobody was looking for. The domain does the market research.
Anyone else validate this way?
Search demand is a useful filter, but I'd keep validating what it actually proves. Impressions show people are looking for something. They don't necessarily show they'll adopt your approach or pay for your solution. That's a different question.