What does ipv6 give you that ipv4 does not?

A public, directly routable IP address which doesn’t cost a fortune for the ISPs. In fact, millions of public, directly routable IPs per user such that it’s an embarrassment of riches compared to ipv4.

And it’s even better if all devices and networks support it, since you know longer have to rely on n layers of NAT, reducing latency and complexity.