There were a few reasons I wanted to switch, but nothing pushed me much, until a lot of things culminated at once.
I'd been using Linux on servers for a long time, and a Linux desktop in an old job, and I much prefer the usability of it over Windows (I really like the command line options on Linux over CMD or Powershell, and kept having issues with Git Bash, whereas stuff would just work on Linux), as well as the customisablity, and it is more friendly for developing (at least in my opinion, web development for me specifically) so I'd been contemplating it and occasionally trying out distros in VMs. Then I found out my PC isn't compatible with Windows 11, and it had me thinking it was dumb that I couldn't upgrade because my PC meets all the specifications but there's some specific thing Microsoft didn't like and didn't think was "secure enough" or whatever. It got me thinking that it's dumb that a company can decide what I'm allowed to install on my PC. Even if my PC was vastly underpowered for the OS, it should be up to me to decide what I can and can't install on my computer that I built with my money.
I looked into installing Windows 11 and bypassing the check, and it seemed like too much hassle, so I was going to stay on Windows 10, but at some point after, a Windows update completely broke my installation - which wasn't the first time - and after hours of trying to fix it, it pushed me over the edge. I decided to completely scrap Windows at that point, because I was just fed up and preferred Linux anyway, and justified it further because of the fact Windows is essentially spyware on top of that. I nuked my OS drive and installed the distro I liked the most at that point (KDE neon) over it and never looked back.
I also have Valve to thank for that impulse too, because at the time I'd been looking at their work on Proton because I wanted to know how well gaming worked on Linux, and from what I saw, pretty much my entire library would work mostly without issues thanks to the info on ProtonDB. If I hadn't seen this info, I might have hesitated to switch, but knowing most - if not all - of my games would work (even if I had to do a bit of tweaking) made the decision very easy.
The main thing that surprised me is just how polished it feels. At least with KDE as my desktop environment, it feels like everything has a purpose and they belong together. So many things in Windows felt tacked on and like it was an afterthought, with vastly different designs. The biggest thing I love is being able to fully (and I mean fully) customise the taskbar, window decorations, colours, animations, everything. I love being able to make things my own, and I couldn't do that on Windows. Windows was more "Microsoft with a bit of my touches" whereas using KDE neon it feels like my computer.
Also, software repositories are fantastic. Instead of having to download an exe for each thing you install and each having their own way of updating, with package managers I can just search in a central place, install it, and the package manager itself will keep it updated for me. It's just so much more user friendly. Although one thing that threw me off with package managers is seeing a notification that I had updates and it was like "you have 200 updates" and it shocked me, but obviously each piece of software has their own individual update, including system packages, instead of Windows update where you get a single package with a bunch of updates in it that you can't customise, and possibly a few driver updates.
One obstacle I hit however was graphics drivers. I have an nvidia GPU and nvidia really doesn't want to play nice with Linux for some reason, but to get a decent gaming performance you need their proprietary drivers. I had quite a few issues trying to get them properly installed, so unless you have an AMD GPU or are fine spending a bit of time possibly troubleshooting, take this as a warning (or if you don't care about gaming, because the open drivers would probably be fine for just a basic PC)
I use kup to back up my important PC files (the basic pre-installed backup software on KDE neon), which backs up to a separate drive on my PC, and that gets synced to my Nextcloud instance on my local server, and that - along with all the other data for my containers running on it - gets backed up by Kopia to DigitalOcean spaces.
I couldn't recommend Kopia strongly enough, because you have such fine control of what gets backed up, when it gets backed up, how many to keep etc. and it is versioned so doesn't grow exponentially, and it compresses and encrypts the backup. I also have a setup where it executes a script before and after the backup starts that stops and starts the containers to maintain file integrity since nothing will be writing to the files. And it's also a Docker container so it can just fit into your current compose setup.