Man, I feel bad for Docker, the company. Created the open source project that almost single-handely revolutionized deployments, development environments, and cloud computing, but sorta never managed to stick a product.
I wish we had tax exceptions for companies maintaining open-source projects full time to be reasonable write offs or something, with strict checks so companies dont just make random "open source" projects to write off, it should be something with known sizable impact and/or use, it would make some critical open source projects attractive "buy outs" or options to fully fund for some of these giants that benefit from them. Imagine if the devs entire salary (up to a point) could be written off completely. Some of these people are working on key infrastructure for the modern web, and even other critical systems, think of Chromium (tricky because of Chrome being not-open source but a proprietary end-product), Firefox, Linux, openssl, and obviously Docker, as good example.
How ? Docker didn't invent the underlying technology and can't control it (through patents, etc...). It's all open and Docker tools are just the most popular but there are alternatives. Why pay when you can get it for free ?
Podman isn't really a competitor at this point, it's just the "docker at home" NIH project from redhat. It works fine, but docker isn't going anywhere really.