Docker is THE solution for self hosting stuff since one often has one server and runs a ton of stuff on it, with different PHP, Python versions, for example.
Docker makes it incredibly easy to a multitude of services on one machine however different they may be.
And if you ever need to move to a new server, all you need to do is move the volumes (if even necessary) and run the containers on the new machine.
So YES, self hosting stuff is a huge use case for docker.
I think your view show the success of Docker but also an over-hype and generation that only know how to do things with Docker (or and so think everything is easier with it).
But before Docker there was the virtualisation hype when people sweared every software/service needs its own VM. VM or containers we end up with frankenstein systems with dozens of images on one machine. And with Docker we probably lost a lot of security.
So this is fine I guess in the corporate world because things are messy anyway and there are many other contraints (hence the success of containers).
But in your home, serving a few apps for a few users you actually don't need that gas factory.
If you wanna run everything on your home lab with Docker or Kubernetes because you wanna build a skillset for work or reuse your professional skills, fine go for it. But everything you think is easy with Docker is actually simpler and easier with raw Linux or BSD.
Docker is THE solution for self hosting stuff since one often has one server and runs a ton of stuff on it, with different PHP, Python versions, for example.
Docker makes it incredibly easy to a multitude of services on one machine however different they may be.
And if you ever need to move to a new server, all you need to do is move the volumes (if even necessary) and run the containers on the new machine.
So YES, self hosting stuff is a huge use case for docker.