Hardware is hit or miss. Had very good experience with ThinkPads.
I don't get the old games part. This is something where Linux absolutely shines, a lot of old Win9x games run perfectly fine on Wine, but fail on modern Windows for weird reasons. The biggest hurdle is usually DRM and Anti-Cheat, but I guess I'm lucky here because I don't play any competitive multiplayer games but more casual stuff. Also I don't use Nvidia. ;)
I just switched completely about a decade ago. Don't even remember what the final straw was. I guess what "helped" was that at the time I was very busy with life and really only had the most basic demands for my computing needs outside of work, so any shortcomings in areas like gaming didn't matter. Basically needed a browser and a text editor. When things got better two or three years down the line, well, it has already been a while since I used Windows, so any shortcomings were just part of life I guess, but also I just figured more and more stuff out over the years. I guess, and that comes down to personal preference, another thing that greatly helped was that I'm just not focused on convenience and somewhat of a minimalist, so I use i3 as the window manager and no further desktop environment. I don't use any file manager but just the terminal. No gvfs, every USB drive gets mounted and unmounted via terminal. I do use NetworkManager but only via nmcli. I guess having grown up on DOS left some impact. It just means less moving parts, so no stupid surprises after an update like "my KDE/gnome file manager suddenly doesn't show any thumb drive I plug in anymore".
I don't pretend Linux is ready for the average Joe. More and more people seem to think so, but I wouldn't even give it to my mom even though her only use case really is browsing the web and writing a letter about twice a year.