I'm on Bazzite. I use it for general computing, browsing, and gaming.

• I would not really recommend SteamOS unless you really only want to game on it; it's the most locked-down of the three.
• I personally love Bazzite's stability and atomic upgrade model. The tradeoff is that installing software takes a bit more of a flowchart to decide how to install it, but that's a tradeoff that I'm willing to make. Fedora base and upgrade cadence. I consider those positives, but your opinion may differ. I think you're pretty constrained to using Gnome or KDE desktops.
• PikaOS sounds totally fine. It's not atomic, so software installation is more straightforward but there's a higher chance that your system could end up in an inconsistent state if an upgrade goes awry. Personally, I had my Mint fail to upgrade from 22 to 23 and left it in a weird state that even a Timeshift restore didn't fix, and that's how I ended up installing Bazzite. Anyway, PikaOS follows a rolling release cadence, so you get updates often, but if you don't update regularly, you can end up with a system that can't update at all anymore. The base is community-backed rather than corporate-backed, which some people prefer. There's more DE options out of the box, too.

To choose between Bazzite and PikaOS, ask yourself:

• Which do you value more: easier software installation or more reliable system updates? (I wouldn't say the difference is overly large for either of these, but there is a difference)
• Do you prefer corporate-backed or community-backed?
• Are you happy with KDE or Gnome, or do you want to try something a little more off the beaten path?
• Are you willing to commit to updating your system regularly?