Heard good things about https://plausible.io/

Probably not. The barebones desktop mode has been integrated into Android core for quite a few years now. So it is safe to assume that it is there in GrapheneOS. But yes, someone should confirm that.
I can confirm that it is present in LineageOS.

Was it Yahtzee? Sounds like something he would come up with.

Do you have time to talk about our lord and saviour, Termux-X11 ?
https://github.com/termux/termux-x11

Still better than that Swarovsky Antivitus

Communities as in what exactly?
The Community Hubs for specific games or various groups that people made?
In either case, it's probably better to intentionally stay out of there, since you know that you generally dislike the content there.
Or, you could try to find a user group that has rules and moderates content in a way that you agree with.
But overall, Steam is platform for video games, which are generally considered to be fun, so it is to be expected that other variations of "fun" will be present there as well.

https://www.pcmag.com/news/meta-adds-interoperability-with-signals-tech-for-whatsapp-messenger-in
https://techcrunch.com/2024/03/06/to-comply-with-dma-whatsapp-and-messenger-will-become-interoperable-via-signal/
I am still interested to know the details of how they came to this decision. Why Signal instead of Matrix.

As far as I know, the Signal protocol was chosen to be the intermediary layer between the existing platforms. Matrix protocol was a candidate, but was not chosen.

Still, if you wish to use a bridge between Matrix and some other platform, then you can either set one up yourself or try to find a Matrix server that already has such bridge set up. https://matrix.org/ecosystem/bridges/

Will it have any fallback systems so that it remains playable even when servers go down?
if not, it is another candidate for stopkillinggames.com

Schools should be the first place where proprietary software should be replaced with FOSS.
Microsoft understands the "get them while they are young" method very well, understands that it is a very significant element of the cycle that keeps them in power, and therefore puts a lot of effort into making sure that this does not change.
So getting children to learn on FOSS and the concepts around it would result in very significant changes, especially in long-term.

Is there any project or organisation that is already trying to achieve that?
If yes, then it would be good to spread the word about them around the internet.