I’ll add my two cents as a long-time Linux user - as in, I’ve been using Linux as my primary OS for about 10 years now. I started with Ubuntu way back then, and have stayed with it - if I had the time to spare, I might experiment with others, but thus far I have been very satisfied with Ubuntu.
I keep a virtual Windows machine on hand for the times I absolutely have to use Windows. For me, that boils down to 1) Logos Bible Software, 2) digitally signed documents specific to the university, and 3) Microsoft SQL Server Management Studio. After so many years with Linux as my daily driver, I absolutely detest having to fire up Windows … and I find myself (as the unofficial tech support person in my department) having to sort out irritating Windows issues as often as I face any sort of Linux bugs.
Other than occasionally playing a few rounds of Oolite (a modern cross-platform version of the ancient C64 game Elite), I’m not a game-player, so can’t comment on Steam or other matters related to gaming.
When it comes to other software, I have not experienced the problems that others mentioned above, of breaking the system when adding third-party repositories - but honestly I do very little of that. These days, most software that is not supported in the built-in Debian/Ubuntu repositories is made available in a self-contained AppImage. Often the built-in repository has a somewhat earlier version (e.g., of Shotcut), but the latest version is available via AppImage. For someone who is not comfortable with a little bit of tech work, this may not be a good option - sometimes one needs to update the permissions on the file to make it executable, for example, and I put AppImage executables into my dock structure manually - not sure if there is a way to make them show up in a menu automatically.
In general I feel that I can find safe Linux programs of virtually any variety to accomplish the tasks I need, much more easily than I can find Windows programs to accomplish the same tasks - or at least, with respect to FOSS programs. There’s always a commercial Windows program that someone is ready to sell … 
With regard to hardware support (e.g., the problems mentioned above with new laptops having trouble running Mint until the Mint distribution catches up), I would say that it is laptops that are going to be most likely to experience this sort of thing, and it very much depends on the type of laptop. In general, I find that Dells are happy to run Linux, while other brands may have one or two oddball peripherals that don’t want to work, or may take a while for Linux to catch up with. Unless your desktop machine is an all-in-one (monitor+computer combo), I will predict that you will have no compatibility issues at all.
Of course, there are two ways to ease the transition / test for compatibility issues. One is to try Linux via a live-USB - basically, you burn a bootable USB stick, and boot from it; you get the option either to try Linux or to install it. Very important: be aware that the live-USB version is going to be way, way slower than the installed version will be, so the goal here is not to judge performance, but rather to see if all of the peripherals work (wifi, etc.).
The other way to ease the transition is, as mentioned above, to install Linux alongside Windows in a dual-boot configuration. I can’t speak for other distros, but Ubuntu has offered this as a standard option since before I began using it. This is how I first began, with the ability to boot into either OS. Linux was able to read the Windows files directly, but not vice-versa, so I kept all my documents in the Windows file structure, and could work on them when in Linux. It didn’t take very long before I realized I was almost never booting into Windows, at which point I went with the virtual machine approach - and it is even possible to share the Linux files with the Windows virtual machine, even though they are stored in a format that Windows doesn’t know - the virtual machine (I use VirtualBox) transparently translates them. Thus, I keep all my files in Linux, but for those few times when I have to use Windows, I can still get to them. It is even possible to cut and paste between the Windows virtual machine and Linux.
Obviously, each person’s needs are different, and thus each person’s experiences will be different - so YMMV!