I guess there's a large pool of IP addresses used by residential ISPs that could be recycled relatively easily.
When I lived in Ireland I only got a public IPv6, my IPv4 was behind CG-NAT. The nerd in me wasn't a fan of that on paper, but in reality I didn't have any issues with it.
I could see ISPs making a quick buck by switching to CG-NAT on IPv4 so they can sell off their IPv4 blocks.
Those IPs being recycled for servers/services doesn't seem too risky, given that they're not typically hosting anything.
When I lived in Ireland I only got a public IPv6, my IPv4 was behind CG-NAT. The nerd in me wasn't a fan of that on paper, but in reality I didn't have any issues with it.
I could see ISPs making a quick buck by switching to CG-NAT on IPv4 so they can sell off their IPv4 blocks.
Those IPs being recycled for servers/services doesn't seem too risky, given that they're not typically hosting anything.