I totally support free/open source software. A number of apps I use on Windows are FOSS. (GIMP, Gnucash, qBitTorrent, ONLYOFFICE are my current go to ones.
I do mix in proprietary apps, but this is usually because the equivalent open source app is not up to snuff in terms of usability. This is particularly true for audio engineering.
I use REAPER as my DAW.
On the consumer audio end of things I use foobar2000 and EAC an audio player and CD ripper. Both are freeware proprietary software. As far as customizability and CD ripping accuracy I haven’t anything better than EAC.
On Windows, I take a practical approach to free open source software. If there’s a great open source free software solution I’ll pick that first. But if I have to pick a freewrare/freemium proprietary solution, I will do so if the user experience is better and the software is well developed.
Of course, the only way to tell if proprietary software is any good to is use it yourself or check forums/reviews for other people’s experiences.