yeah, Docker might be dead, but the technology behind is not (thats what I was refering to) ... whatever, let's call it OCI container, whether it is kubernetes, podman, runc, docker, containerd etc. that runs the application container does not matter. Just wanted to point out that there is an interesting application container project for FreeBSD growing
The truth is that Docker is commoditized product. Docker's "decline" is a product of their own making, they are just a leader in a piece of software that's easy to replace.
Docker thought they would give their software free and open source so everyone would use Swarm. But then Kubernetes came along and everyone used that, and hence Docker is struggling. Docker is just the container engine, abstracted behind Kubernetes.
Docker might "re-focus" on "Developer Tools", but why would I use something with the "Docker" name instead of the tools my cloud provider gives me and not worry about another bill? Just because Docker was "cool" and "upcoming" in 2015? Look at HTC, they were "cool" 10 years ago and now HTC is history, they lost to Apple, Samsung, and the various number of Chinese OEMs.
Look at Hadoop vendors like Cloudera, they once had the world come around them in 2011 and now Hadoop (and Spark) is just a managed service in AWS or Azure. Why use "Cloudera" when I can just use the Hadoop which comes with my cloud subscription? Same applies to Docker.
In comparison, look at Microsoft. Say what you want about them, but a lot of companies use Microsoft products mainly since they only have to worry about one vendor for OSes, productivity software, and cloud. Many (not all) Microsoft products have "alternatives", but a lot of companies are Microsoft shops since they're the one-stop shop for a lot of an enterprise's software needs. But at the same time, many other companies may go with AWS or Slack or Zoom or Google Workspace and just use Windows and Office.
The one-stop shop analogy can be said about networking with Cisco and Huawei respectively for enterprise and service-provider roles.
Docker has essentially become plumbing. Plumbing that isn't exactly BSD-friendly so we have to rip apart Dockerfiles and build systems in order to put newer software in Ports. Hopefully Docker will eventually get abstracted out of DevOps so we are able to get portable software again. Or maybe what systemd was to the desktop, Docker is for the server: the thing we hate but have to deal with to get software out of it indefinitely. a pain for Ports maintainers but "loved" by developers who only think about Ubuntu on AWS or GNOME on Fedora.
Disclaimer: I work at Microsoft, but not on Azure. I do however deal with the Azure "Big Data" ecosystem heavily.