99% of the time I hear people talk about product-market fit in crypto

If the question needs to be asked, it hasn't! Seriously -- Product/Market Fit means the market is pulling product out of the company faster than the company can make it -- it's unmistakable when it happens.

Related
https://warpcast.com/pmarca/0xaa98d2bb

What if, what if the supply is somehow constrained due to artificial, on purpose or just being lazy.

I guess if I keep on saying no to many invites, that means I have product market fit.😆

So with that definitions: BTC, ETH and Solana has definitely PMF.