If you sell it on Steam or the Mac App Store we’re talking about a minimum of 30% gone off top.

Marketing costs money. Taxes, etc. Not everyone is going to pay the full 150$. Various discount programs would probably exist.

Anyway, even if my numbers are off not enough people will pay for a browser for this to be a viable business.

If you disagree you can start today and I’ll gladly subscribe. Not a fork, no build a new browser from scratch with feature parity to chrome