Chromium doesn’t need Chrome to exist either: it’s a separate project and if Google doesn’t want to support it anymore, someone can easily fork it to continue having Chromium-based browsers. That’s the property of open source: anybody can inspect and fork it.

Edge and Chrome are both closed source and owned by companies, so your comparison is just not valid. Using AOSP is certainly not supporting Google’s monopoly: AOSP is totally open source, was bought by Google a long time ago and they don’t own it due to its license (aside from the name maybe). Meaning you can still flash Android on a system without paying or using Google’s services or products.

It’s like saying you contribute to Google’s monopoly because you use Linux and Google (also) used it in its Chromebooks.

I didn’t have to spend hours getting my GPU to work on Linux… What were you using exactly, as a distro and as a GPU? Not that I try to invalidate your experience, but afaik, if you have a AMD or Intel GPU, it should work out of the box and if you have an Nvidia GPU, any user friendly Linux distro that is optionally made for gaming have drivers preinstalled and can easily be updated through a GUI or a two words command so that you can directly play as soon as you installed the distro.

You have to give them a reason to get interested in the OS and the programs they’re using. I gave Linux a try because I was concerned about privacy and I wanted to use more ethical and user respecting OS and software than what I used at that time. Linux and the FOSS world was an obvious choice for me. Custom ROM on Android was sort of the bridge which allowed me to transition. If it wasn’t for that, I would still be on Windows and I wouldn’t learn that much on how an operating system works and what differentiate them, aside from the look. The fact they’re kids or that they play games have nothing to do with it: a lot of adults don’t know either what type of OS they’re using, despite it being in their best interest. The problem is that we don’t give or show them the reason they should be interested, or at least be curious about it and most of time, before people get a degree, we end up killing their curiosity.

As they play Minecraft, you can advise them to switch to Prism Launcher instead of the minecraft launcher, especially if they mod the game, it’s much better for that. It could be a good start.