Could be small or big.
My answer has always been that, Linux can't handle everything I'd ask out of it that I normally can with Windows. I know the games issue has been progressing far from the days when that used to have been an archaic flaw with Linux for the longest time. Games might not be the issue except for some concerns I have for some games.
I was taking some time a few moments ago, to check if a program called Firestorm Viewer would work on Linux Mint which could've been my distro of choice. And the description written on the linux page described exactly the kind of concerns I'd have for compatibility and usability from going Windows to Linux.
They said that their viewer was tested and designed to function mostly with Ubuntu and while it could work with other distros, it's not to be expected to be smooth.
That's the kind of sentiment and concern I have always had with Linux if I were to go from Windows to it. There are programs and tools on Windows that I have that are used for specific purposes and I know they will not function on Linux. Furthermore, incase anything breaks down, any and all solutions would only be applicable to that thing that would be far easier to solve than just being SOL if I was on Linux.
It is something as a user that I just can't simply afford to deal with on a regular basis if I made the switch.
So while I may not have too much of an issue running games, I won't have too much of an issue using alternatives, I won't have to deal with the Windows ecosystem .etc I will just be running into other walls that would simply make me second guess my decision and make me regret switching to the point where I would dip back into Windows in a hurry.
Every couple years I decide to switch to Linux, spend few weeks trying to get everything to work right, then give up and go back to Windows.
I feel like I'm in a "Goldilocks zone" where I'm enough of a power user that doing what I want in Linux takes quite a bit of work to get set up, but not enough of a power user that I enjoy the technical challenge.
Most recently I was trying to play a couple modded video games, and run a headless HTPC. One thing would work on one distro, another would work on another, but I couldn't get everything to work at once.