See, the thing is - as a new HA user I have zero clue what Node-RED is, what it is used for and how it is supposed to be used and how it is not supposed to be used. Or deCONZ or Ada or ZwaveJS. All I know is that functionality is added to HA by “integrations”, so when I get said in a user forum that “that thing you want to do is much easier with Node-RED” or “your device will only work via deCONZ”, then first thing that I will go to is to install an integration with the same name. I do not even know what addons do … because it is impossible for me to just install and try them on my HA installation. A user does not want addons a user wants more HA functionality and some of it is locked behind addons.
In some cases this actually works just fine - (I had no need for deCONZ or Zwave, so I just tried that now) the integrations for deCONZ and Zwave JS have a Help button and then in the integration docs there are actual instructions on how to start the required external servers with Docker and how to pair them with HA. That is awesome.
In other cases, like Node-RED, well there is no integration there and the user is lost. The interest is not to “use Node-RED” or learn the Node-RED infrastructure, it is to get more functionality in my HA installation. As you said - there are far better and easier ways to, for example, get SSH/Šamba access or install MariaDB or NGinx server on your computer. People with containers do not need support for that. But for external things that do actually integrate into HA and add to its functionality, there more straightforward documentation or scripted assistance would be welcome.
And to be clear, I do not want to run Supervisor for this to happen. It is not even possible to do so in most setups where HA is run in container. If HA is running in a container, then whatever solution is there for addons must also be run inside a container. Either the same as HA Core or a separate one.
If you are saying that a user can easily get the same functionality on their own, then it must also be possible to generate some combination of docker-compose config, derived Docker containers and HA configs that would also enable the functionality. And then expose them via the same Addon Store interface. Without any Supervisor at all being in the picture.
Or at least a documentation section describing step-by-step how to get a few common addons running and integrated manually. deCONZ and ZWave JS integrations are really close to providing that documentation, so they can just be linked from the main documentation pages. That would be a really easy win. Having a couple more examples for how to install and enable an addon that does not have an integration of the same name readily available would help a lot, including an addon from community, explaining exactly where to find the information about: what extra container needs to be started, with what Docker settings, with what configuration of the server inside and where to find out what settings need to be set in HA. If that is generic enough so that the user can then look at Awesome Home Assistant and apply the same procedure to get (most) other addons working on their own would be a major win for usability and user education.
P.S. That “excellent doc” link opens to an empty page for me, just the headings, no content