It took Podman a good 2 or so years to develop a good docker compatible http api. I presume that's why. There's no point in coming out with all of the features when they can release with some support, and add on top of it.
Even today, some docker-compose features still don’t work with podman. There’s just an absurd amount of subtleties and edge cases, but pretty much all my usages hit one of these or another.
Biggest reason is that docker / podman/OCI are very different architectures and security models.
I hope there is something new. The tooling and deployment fragmentation is a nightmare.
From a security and open standards pov, we maybe should be moving to podman/OCI.
The docker tooling was often focused on the dev experience and it showed, but it wasn't a system with a good security model and this transition is a large part of that pain.
To be honest, I'm not sure why they didn't already release it supporting a compose-like tool. But my hypothesis is that considering they release a v0.1.0, they tried to be lean on their CLI and maybe they're building something on top of it.