It's a 2014 Lenovo that was probably sold with Windows 8.1 but had been upgraded to Windows 10 by the time I got it.
I wasn't using it much anymore and the last Windows 10 update did not go well, with the machine rebooting itself several times before it claimed to be finished. Over the years this machine has become increasingly sluggish with each update, but this time it was intolerably so.
Usually I can track down the problem, removing whatever cruft Microsoft updates inevitably bring, but I couldn't be bothered to do this again. I'm no longer using any software that requires Windows, not even for work, and the machine was so sluggish it was useless to me.
So I backed up all my files to an external drive, downloaded a net-install iso, fiddled with boot order on the laptop setup screen, and it all just worked, no more Windows 10.
With Linux installed the machine is quick and crisp again, probably quicker than it's ever been.
That's what I like about Linux.
But I never tell anyone who is unfamiliar with Linux to do this with their primary computer. There are too many pitfalls, it's not a trivial upgrade, and things can go wrong. It's best to learn Linux on a spare machine and choose a Linux distribution that has a novice-friendly community. Mint or Raspberry Pi OS are good starting points.
When I first signed onto DU I was using Windows 98SE. That choice was largely determined by the availability of the latest web browsers. When these browsers became available for Linux I quit using Microsoft products on my personal computers and started telling people I'd only use Apple or Microsoft products if they paid me.