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.
I tried messing with my boot settings since it was required for playing the new battlefield open beta or whatever. After changing the settings, my computer could no longer find the boot drive and I was stuck in BIOS. Managed to revert and everything was ok, but with all that will be involved in transitioning to Linux, I don't feel like risking my PC for that when everything works now, as much as I would love to be on Linux.
I know dual boot exists, I'm not interested - have to cut my storage volume to do that and I'd rather it be all or nothing.
I know I can test drive Linux by booting from a USB drive, not interested cause I've already done it in the past and it was fine, but it doesn't fix the issues with transitioning.
I know I can back up all my data and proceed from that point - so what, all my data is backed up, my drives are formatted, and then what do I do if I run into the issue of not being able to boot from that drive again? Or even another issue I don't know about yet that bricks my shit?
Beyond all of that, transitioning will involve a lot of work and investigating to set everything as I like it and fix any problems I run into. I only have so much time in the day and so much attention to give things and with the risk consideration added on, it's just not worth the time and effort and attention it would take.
That said, I'm considering once I get a lot of free time to commit to it somehow or I replace my current pc