If you mean what made me uninstall Windows, it was actually just not being able to do anything I wanted to do on Windows. I was already using WSL for most basic things and tried to set Windows up to be as similar to a Linux distro as possible eg only installing things with a command line package manager and looking into trying to get it to behave like a tiling window manager.
The biggest things were not being able to use some of my preferred software, e.g. my preferred PDF reader Zathura, and just having no clue what any of the commands were whenever I had to use PowerShell or CMD. I only really knew how Unix-like systems worked and was frustrated with my lack of familiarity with Windows and how their OS works.
The only reason why I kept a Windows partition was for gaming, but at this point Proton is so good there’s really no need for a Windows partition. And I rarely play video games these days anyway.
If you mean why I started using Linux, no reason, I’ve just always used it from a young age.