If you live in the USA you don’t suffer from the problem it solves because you have ~5 IP v4 addresses per capita (totaling to 41% of all the IP v4 addresses), and likewise many european countries have ~2 per capita (although there are expeptions like Italy and Spain which are a bit under 1 per capita). However many other countries don’t have such luxury, for example in india there’s one for every 36 people, which is obviously not enough and thus they have to either use NAT everywhere or switch to IPv6.