Poke me if you need help, since I run one.
NafiTheBear
It is in the title. And alxd kindly even linked the artist directly.
There is a list of some companies on the homepage: https://www.econgood.org/who-is-ecg/ecg-companies/
It is a bit hard to give you a good answer myself as companies that I know are probably none that you know, but there is also an interactive map on that page.
Ohhh I didn't know they are on mastodon I hope it was OK of me to repost it, but tumblr really started to throw me a login page recently, which hides half of the comic.
I use smartgit it serves me well: https://www.syntevo.com/smartgit/
And it has all 3 of your criteria as far as I can see.
I recently watched downsizing, whose main topic was overpopulation and I remember a time where there were some papers on that the earth will soon be overcrowded and I'm very happy that this simply won't be an issue for us in the future anymore.
"It magically appears in flatpak only after you've installed it by other means"
I kid you not this happened to me 3 times already.
I'm one of the guys on the couch.
The megalodon author themselve recommended to use moshidon and is considering becoming a contributor there.
This is a valid mention and I agree, but I also have to say that there are companies like the nextcloud corp itself who do offer that level of expertise and are German based and would use the money to improve nextcloud, which is open source, whereas we don't know how much of the money that Microsoft takes goes into the open source project.
It was intentional play of words. :p
For the time being take my shameless plug https://bears.town/@NafiTheBear/113317211352339069 It is mainly for art though.
There are a couple others for (fursuit) pics