I'll be slightly contrarian to others and give a different perspective: you may find yourself hitting some roadblocks, I'll try to explain.
I set up Linux Mint for my elderly parents. The key thing is, I set it up for them, functioning as the administrator for that machine, making sure they had a non admin account and configured their desktop to only show the shortcuts they cared about (firefox).
It worked fine, and I only got calls once every few months. They got scared if some popup occured, or if they accidentally saved something to their desktop that they wanted to get rid of. I don't know if that really meets the definition of seamless, and I don't know if you'd even consider those problems.
The other thing that can happen, is hardware interfaces. I know that you've listed out your use case. I'm just saying that if your birthday rolls around and someone buys you a 3d printer where you "just plug it in", you're going to be in for a long troubleshooting day, if it isn't natively supported.
With Steam games, you can often get away with enabling proton, but... Small issues like being able to select multiple drive folders have sent me down long troubleshooting avenues as well. And when I use the word troubleshoot, I'm inevitably referring to the command line.
Lots of people are encouraging you to try, and you can make that decision. I just want to toss out that it might not be seamless. But I don't think Windows is seamless either. It's just what most people are used to.