Our local German teledata internet provider uses CGNAT, and it is a mess of random timeouts.
I could see that that's how IPv6 adoption happens.
ISPs realize that selling their old squatted IPv4s to Amazon/Google/Azure more than pays for the transition to IPv6 + CGNAT with a tidy profit on the side.
Then to save more money, they cheap out on the CGNAT so that IPv4 connections have poor performance.
Customers complain to the slow websites (since google/cloudflare sites all load quickly, it must be the site's fault) and they have to adopt IPv6 for that reason.
Legacy account on Vodafone (from Kabel Deutschland days), no v6, no CGNAT.
Vodafone refused to enable dual stack on my DSL connection. I got to pick from either keeping dual stack with CGNAT or completely disabling IPv6 but get a reachable IPv4.
My mobile provider doesn't allow IPv6 connections.
So ironically, to be reachable from everywhere, I had to turn off IPv6.
So everybody is using IPv6 in their home networks without problems.