I have 5 computers in my household and can't afford to replace all of them.
Mountain Man
I have only a few applications on Windows that I need(*) for which I don't have either good Linux substitutes or I can't/don't run under Wine or in VirtualBox on Linux. My wife uses Linux and for a number of years simply presumed it was Windows. She hadn't realised it wasn't.
BiaB is good but imperfect under Wine, though a few little things actually work better under Wine than on Windows.
(*)I have a PCB CAD system that won't render layouts under Wine or VirtualBox.
IIRC, that's it, though I'm sure there are other things. Video editors are sometimes still a bit limited and a bit fragile. I have 7 computers here in pretty-much everyday use. Two of those are ITXs (my main file-server and BackupPC in an outbuilding), one is a Raspberry Pi (DMZ and mail transport). None of those three, nor my studio PC even have Windows on them.
I
do though have around 40 years experience with Unix and Linux systems and I'm perfectly happy using the command line for some tasks. Indeed I prefer it for some tasks.
Oh, BTW, I have no objection to paying for software on Linux and I'll make donations to help support the free stuff. To me that seems only fair.