If you've interacted with me, you know I push for IPv6 everywhere(ex. https://gitlab.syncad.com/hive/hive/-/issues/381 might have to implement this myself in the future unless one of the current hived devs tackles it).
My biggest reason to want support IPv6, the cost. IPv4 is expensive. AWS recently announced that they are going to be charging $3(ish) a month for IPv4 addresses(https://aws.amazon.com/blogs/aws/new-aws-public-ipv4-address-charge-public-ip-insights/). ARIN's IPv4 waitlist still hasn't given any to requests back from July of 2022(https://www.arin.net/resources/guide/ipv4/waiting_list/). I've heard that requesters might be waiting 3-5 years to get more from the waitlist. I planned on getting back on the list, but after hearing that, realize it's not worth it. Ripe's isn't much better: https://www.ripe.net/manage-ips-and-asns/ipv4/ipv4-waiting-list.
The more that providers have to pay, the higher the fees are going to be for you. Learning IPv6 isn't hard. There seems to be so many network admins who just don't want to touch it, saying they'll be retired by the time they need it. Similar concepts as to IPv4 apply. If you know the basics of networking, you can learn the rest fairly quickly.
The truth is, most software can support IPv6 out the box. We aren't hardcoding IPs in most places, DNS is the way to go. All the people with simple webservers just not taking the extra step of pointing an AAAA record to their server aren't helping. Caddy can do IPv6, Nginx can do IPv6. I run a lot of things on an IPv6 only internal network. It's very easy to do, and with the magic of NAT64, I can get still reach the IPv4 world when I need it(which is mainly to github, once they fix their issues, I'm probably going to try running IPv6 only without NAT64 more and more).
So come on and be good to the internet and help promote IPv6. Use it. Learn about it.