Are you running any servers? I can't find it now, but I remember reading somewhere once that ISPs force IP changes more often on residential users that they detect are running servers.
I've been running a web server for the last year or so, and I still have the same IP from Comcast that I've had for years. When I was a teenager I also ran servers and had a stable IP for years. Ostensibly they say you're not allowed to run servers, but I'm guessing they'd only care if you're constantly using a significant chunk of your bandwidth.
Sure. I still remember when I could order additional static IPs on residential cable internet.
That doesn’t mean most getting online today in Asia or Africa basically have a choice other than CGNAT IPv4 and IPv6 from their ISP. Your own dynamically assigned IPv4 is a relative luxury.
At least until the 10G fiber upgrade happens, Sonic has given me a static IPv4 address for a decade.