Then it's not a shitty ISP. My precious ISP not only put that customer behind CGNAT, the CGNAT's IP addresses they use have poor reputation too so their customers sometimes get caught in captcha hell (very annoying when cloudflare doesn't like you because every other sites are behind cloudflare now), doesn't provide static IP address even when I asked to pay for it, and don't even provides IPv6. The only saving grace was 1:1 download/upload ratio, and they implemented government-mandated block list half-assedly (Reddit is banned in my country) so it's easy to circumvent. Once another ISP covered my area, I immediately jumped ship.

The new ISP also has problem with IPv4 allocation. Sometimes I got assigned behind a CGNAT, but restarting the modern is usually enough to get assigned into a publicly routable IPv4. And they actually have IPv6 so the CGNAT isn't as much of an issue. The drawback is asymmetric download/upload speed, and they implemented the government-mandated block list more competently (transparently hijacking all DNS requests, throttling DoH, ip-blocking some blocked websites, sniffing http host header and block it if the website is banned, etc) so I have a bit harder time to unblock everything.