I don’t have all the answers That’s what the hashtag #asknostr is for

I think eventually the full nodes will be built into Wi-Fi router boxes Actually start 9 is already doing that… So on a long enough time scale Probably every household that has internet will by default run a full node

This is unfortunately wrong, most people have no incentive to do that and it wouldn't provide them any value

I think you're right. Moors law doesn't stop at physical hardware - if the cost of everything falls forever, then there's just no reason not to have all the important stuff.

What data source are you looking at? Bitnodes.io definitely estimates many more now than there were in 2017. Same with Coin.dance.