I don‘t think it is a binary situation: Complete self sustainability vs. full dependence on large corporations. Rather it is a spectrum and everyone feels comfortable somewhere else on it. Also I don‘t think the ends really exist, as someone else will always have power over you (you can‘t reasonably maintain everything yourself) and you can always migrate/quit from a service. Over time your position might change. For me personally I think Tailscale is a great service and for someone just starting out I would definitely recommend it. I think a lot frustration can be avoided when you don‘t set your self-hosting goals to high at the beginning. You can always update your setup later on.

I‘ve actually when something like this will happen. A few years ago German energy providers and distributors needed to split, because it gives you an unfair advantage if you own both. Whole companies were split in two. People working for years together would no longer work together. In the end consumer were much better off after the split. I feel the same way with internet browser. It is unfair if you own the infrastructure (Chrome, energy grid) and the services that run on it (YouTube, power plants).

Has anyone tried it? I am thinking about using it on some Raspberry Pi 5.

Yes, in the sense that you are responsible to update the Docker container and often this can lead to vulnerable containers. No, in the sense that it is much easier to scan for dependencies inside a Docker container and identify vulnerabilities. Also most containers are based on Linux distribution, so those distribute the security fixes for specific libraries. All you have to is update the base image.

Dependency-free doesnt mean they dont have dependencies. Its just that they bundle them all in the executable. When there is a security vulnerability in a library on your Linux system the vendor of your distribution (Canonical, Redhat, SUSE) takes care that it is fixed. All dependent software and libraries are then fixed as well. All I say? Not the ones which have been bundled in the executable. First they need to find out that you are affected and then the maintainer has to update the dependency manually. Often they can only do this after there has been a coordinated release of the fix by the major distributors, which can leave you vulnerable no matter how fast the maintainer is. This is the way it is in Windows. (This was a short summary)

There is plant-it written in Java and HortusFox written in PHP. Both using MySQL. Is there anything available which is written in Go or Rust and uses SQLite?

Well thats what backups are for, but may be start with a mirror or with unimportant stuff for at least a year ;) Also proprietary service can delete your data, too. This happens especially when you are using the generous free tier and they decide to make more money. See Evernote, Gitlab, Heroku…

Get a Steam Deck and use any Controller you want ;) (including the corresponding controller glyphs for many games)

Some cruise ships equip Starlink nowadays