There’s a graph on the linked page, but I’m not quite sure what to make of it. According to the overall trend “SteamOS Holo 64 bit” seems to be decreasing but “Arch-based” (which is also what SteamOS is) seems to be the one that is going up the most. Fedora has only recently started being tracked, but they probably came under “Other” before.

I used Bitwarden for a long time and it was easy and convenient. I’ve since switched to KeePassXC which is less convenient, but it’s more private and secure because it’s offline. I wouldn’t recommend it to someone less tech savvy unless they are just going to need access to their passwords on one device as setting it up reliably with a cloud solution isn’t always simple.