Generally, you want backups in three places, at least one off site for anything you deem important, so now’s a good time to start. SSD’s should travel fine as long as you take the right precautions regarding physical and static damage. Steam will handle most cloud saves, as will some other third party launchers. If you’re coming to the UK, I recommend Scan as a retailer.
Bazzite use the home theatre version for a console like experience. Or go with the desktop versions Gnome and KDE both work really well however the emudeck devs have programmed it to work with KDE if you wanted to use that go with KDE.
You are correct, it’s been on a downward slope since about 2021 but had a another sharp dip this morning probaly following the news they were delaying Asassins Creed