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 made the change about a year ago now. I saw the end of Windows 10 coming up and decided to install linux in a dual boot and try my best to use it exclusively for a couple months until I properly got used to it. You will need to accept that not every program you use on Windows will be available and you may have to try out a couple replacements before you find something that works for you. But most things have decent alternatives. Especially considering how much is done in a web browser these days, there aren't too many programs I really miss from Windows (mostly 3D CAD and RAW image processing).
Also, note that the differences between distros is way overblown when it comes to compatibility, it is mostly just a case of whether your package manager has the packages you want available and how bleeding edge the packages your distro uses are. Debian based distros (e.g. Ubuntu and Mint) tend to use slightly older packages than ones that are rolling release like Arch which should theoretically be a bit more stable.
This is something I need to learn how to do - I've no idea how dual booting works, but I could do with learning. Did you have any good resources to help you, or did you already know how to do it?
Dual booting is easy as long as you have a second drive or can shrink your Windows partition to provide space for your Linux install (this can be done within Windows). Your distro installer should have a couple options during install, one of which should allow you to install it on a specific partition without touching your Windows partition. After you select that option it should install everything including a bootloader like GRUB or systemdboot that will allow you to select Windows or Linux on startup.
A warning about dual booting though, Windows doesn't like to be installed alongside another OS, it may realize this and fuck with your bootloader resulting in a system that won't boot into your linux install. You need to boot up a live CD and do something called "chroot" into your sytem to reinstall your bootloader. Its not actually that difficult but can be a pain to figure out the first time. https://discovery.endeavouros.com/system-rescue/arch-chroot/2022/12/