I write this from Firefox running under Debian GNU/Linux. The computer I write is on was purchased out of income I got from (from other things) creating programs in Python, using Django web framework, and deploying them alongside Nginx.

Firefox, Debian, Linux, GNU stack, Python, Django, Nginx ... all are open source (and so are hundreds or thousands of other software parts I use daily).

I, personally, have immensely benefted from open source and free software. So have uncounted millions of other people, including, most likely, you.

Inkscape and Krita users are not exploited by Adobe, LibreOffice users are not exploited by Microsoft, and so on.

There are plenty of regular users who use open source software to avoid monopolies and abuse.

No like me, I run Linux at home

Not everyone chooses to be liberated but I do