There absolutely are remote first roles in the US, but the competition is also extremely intense. The median SWE and HNer wouldn't make the cut.
It also requires a level of maturity, clear thinking, self-starterness, and independence that is hard to come by without a proven track record and experience.
My advice is for the median/average SWE and HNer, not for the truly exceptional.
Spending a 7-10 years in a hub and then going remote first is the best path because you build the network you need to get referrals to vouch for you as a remote-first hire well as the track record needed to go remote-first.
7-10 years is too much. 2-4 is around the range I would give.
Its also nothing new; new grads gravitated towards these hubs anyway. Previously, they would settle down in the burbs. Now they're migrating anywhere in the US.
2-4 is too little - not enough time to show value nor build an entrenched network that can refer you long term.