The problem is OSS software not even trying to compete with the market. People using OSS software taking it for granted that the UX is going to be subpar, and it really is. Regular propriety software faces the risk of their users not paying, therefore adapting to make end user experience great. OSS usually doesn't have that risk. Open source needs to be exposed to risk from end users.
I tried to change that with Notes[1] but I find it hard to live on solely on ads. I tried to incorporate paying for some premium features (like Kanban) but the app is still fully FOSS therefore everyone can compile it from source easily.
I think I'll close-source my next app[2] before it launches. I just can't risk not being paid for my hard work. I also believe the Linux community will benefit from that, since getting paid will allow me to invest more in making UX-focused apps on Linux. I might open source some parts of it tho (or maybe all of it in the far future).
[1] https://github.com/nuttyartist/notes
[2] https://www.get-plume.com