Maybe they changed it since last year, but it wouldn't cache layers for me. Everytime I'd rebuild the app, it would re-run all the actions from the Containerfile. So a whole npm install each build even though I only changed a source file. Building the exact same file with Docker cached every layer as expected, so a config change would only change the last layer and be basically instant vs 5 minutes.

The other issue with pushing to a registry was that it made a whole temporary tar of the image, then gzip it to disk again before starting to upload it. It blew up the disk space I had allocated to my VM really fast, and made uploading those images take minutes instead of seconds. Docker again seemingly does it all in a streaming fashion as it uploads, making it much faster.

This could have changed though, it's evolving fast. Just didn't fit my use case then. But because of those experiences, I'd say it's probably a safer bet to learn Docker first since documentation is abundant, and there's no little "oh I'm using Podman and have to use a slightly different syntax" gotchas to run into to make it hard for you.