How are they better?

IPv4 is simpler. IPv6 was designed for a world, in the 1990s, where it was expected that every host wanted to be routable. SLAAC etc were all natural consequences of that. For today's use cases, the v4 NAT public/private thing actually turned out to be nicer than v6 global routing. There's still confusion today about whether devices are exposed on a v6 network because the spec itself says default-deny firewall is optional. They had to recently add privacy addresses. The other kinds of v6 addrs like link-local and ULA add more complexity. V4 addresses are easy to remember, which v6 advocates keep saying doesn't matter but it does. The details of managing v6 networks are actually quite messy, as you will find on online help forums for v6 among experienced users who you cannot write off as just being too used to v4.

The v6 spec also has all these alternative ways to use it more like v4, commonly brought up as a cop-out against the above criticisms, but that's actually part of the problem. The spec is too big, and things only implement a subset of it, see Android not supporting DHCP6. Realistically you'll have 99% of people using anything like this the default way, and the spec does define SLAAC as default.

But you could say v6 is better just cause it has more addresses, and that's fair.

...Imperial is better than metric because it lines up with everyday usage better unless you're specifically concerned about the physical properties of water. Especially ˚F vs ˚C. Not a big deal though.

They are better for human consumption/understanding. Have you ever had to type an IPv6? It's awful.