Looming back it was probably Windows XP as the last time I used Windows as my main OS. I switched not because Windows was enremovedtified like it is now, but because the FOSS movement sounded interesting to me. I loaded Ubuntu on an old laptop, and once I got drivers working it covered everything I needed besides gaming. As I became more of a casual player I used Windows less and less until now where I only use it at work. It’s been an interesting journey.
I was going to mention postmarketos if they really wanted to dive headfirst into the degoogled life, lol