I am running as many IPv6 only services as I can.
All MY core services that I use daily are v6 only.
At the end of 2024 i am still shocked to see how much new software does not work without ipv4.
My most recent struggle was with Seq - the opentelemetry server for example.
It is full of new software created in the recent few years that just refuses to work without ipv4. And not because it need to reach some server on the internet. It just does not work if you do not have ipv4 (even private).
The software which Habgdnv was referring to? Seq being their most recent problematic encounter, but there's apparently more. I don't know the details, you'd have to ask them.