IMO, or atleast when we were making that decision, a key factor that we considered: Since docker has been more ubiquitous as a technology and millions of users have already been running docker in their infrastructure (and containerd under the hood without even knowing that it exists), containerd has seen the test of time a lot more than e.g. podman.

Also to add, containerd as a system is very pluggable and flexible. You can swap out an entire subsystem and write (plug) your own with containerd. e.g. you can write your own custom snapshotter and use that if you don't want to go with the default. e.g. The firecracker-containerd project (https://github.com/firecracker-microvm/firecracker-container...) wrote their own devicemapper snapshotter. From my limited understanding of podman, I believe it's geared more towards security and making containers rootless, which was a pain point in docker initially, since everyone ran containers with root.