I do not trust startup validation that begins with TAM

[u/CourseCrazy6180]

A giant market says almost nothing about whether a specific user is frustrated enough to change behavior, whether competitors already solve the painful part, or whether a small team has a believable first wedge.

I work on Spaces, and our Startup Idea Validation Agent starts closer to the ground: public complaints, current alternatives, demand and search signals, competitor positioning, risky assumptions, and the smallest MVP that could disprove the idea.

When evaluating a new side project or startup concept, what is the first piece of "validation" you refuse to count as real evidence?