Why isn't FOSS software being distributed trough Microsoft, Apple and Steam store?

Hello @st.raw

And it’s a niche that doesn’t really buy software. Expect lots of praise, but no money.

I suppose you have a point here…
Of course one can not summarize since every Linux user is different…

IMHO, the biggest problem on Linux is that there are not enough artists, right now, using this platform to make a difference. In the long past, most artists worked mainly with Apple hardware for instance.
I have just read some of the last comments on this forum about the Wayland color management to confirm this hunch [1].

[1] Wayland color management - #488 by David_Wilson