I recently moved house and looked at a new offer from a new ISP for a long term lockin but a cheap price. They used CG-NAT. I instead chose one which gives me as many ipv4s or ipv6s as I can reasonably use, doesn't oversubscribe its upsteam connectivity etc.

For home internet service I would prefer to pay extra for a better service, it's too important to try to penny-pinch 0.1% of my income on it.

But then I live in a capitalist country where there's competition, I believe some countries you don't get a choice.

FYI it's practically impossible not to oversubscribe your upstream connectivity unless they either spend way too much money or offer very slow service to users. Consider ten thousand users with 1G connections - should they have 10 terabit upstream?

The more practical thing to look for is that they aim to upgrade it based on need, instead of arbitrarily throttling the users.