Docker is every bit as open and not locked in as podman. Perhaps even more so as it's so widely used and doesn't require redhat specific projects around it. Are you confusing docker with docker hub?
Well sure, then let's talk about podman desktop. I'm pretty sure the discussion was around docker itself, but maybe I got confused... Because otherwise you can just use other tools rather that docker desktop to manage docker containers (eg rancher desktop, which is also open source).
Oh yeah to be clear, I absolutely agree that docker desktop as a whole is a mess especially since they keep introducing more ways to tie it up to docker hub etc. I wouldn't use it unless I'm on windows. So yes, avoid docker desktop but docker (the engine) itself is thankfully completely separate from docker desktop.
Docker still sees a ton of development. I wouldn't be surprised if it sees more dev than podman.
And my point was more so that podman is obviously designed around the rhel ecosystem. I'm not saying it's closed! Just that even if we were to (wrongly) argue that one of the two is more "locked in", it's clearly podman. Docker is so much more widely used, ported, is basically as completely "non locked in" as it could be.
The only possible "lock in" is maybe the docker images namespace defaulting to docker hub but imo that's trivial and basically more of an early design choice that can't be reverted.
By all means, we can argue about technical differences but the often repeated argument about docker being less open than podman or whatever is just not true
Podman Desktop is completely open.