What pushed me over the edge was how much worse the user experience became with 8 & 10.
I really disliked the lack of control over updates, settings and defaults being reverted after minor updates, and the constant pushing of Microsoft accounts and services. The data collection and privacy issues certainly didn’t help either. I switched from 7 to 10 for a period of time, but eventually started using Linux for everything except for games. I started realizing just how good Linux gaming was getting, and I eventually had one too many issues with my Windows partition and just quit using it entirely.
I don’t remember having a lot of the frustrations I hear some talk about when switching, but I think that was because early on I realized I just needed to start figuring out the Linux way of doing things rather than bringing my Windows experience over.