Maybe it's good enough that not very many people care. I moved around San Jose, Mountain View, Berkeley, and Sunnyvale, never noticed problems with Comcast or AT&T. Was expecting flakiness after hearing all these bad stories, but no, it was reliable.
What you don't get often is fiber-to-home, or great upload speeds. But most people aren't running big home servers.
CGNAT isn't a matter of cheapness. There are more Internet users than IP addresses. Someone has to draw the short straw, and that's the providers that came late to the party.
Now, if they're doing CGNAT and also don't have IPv6, that's just crap. They shouldn't be allowed to call themselves an ISP at that point.
What you don't get often is fiber-to-home, or great upload speeds. But most people aren't running big home servers.