Preface: I don't have any experience with Garuda or Nobara but I have used Bazzite.
Not to make the choice harder, but Bazzite does come with Plasma 6. You can have it boot to the SteamOS UI or to the Plasma Desktop.
Bazzite is a great choice for stability but you need to be aware it doesn't operate like a traditional Linux distribution since it's based on ostree and is immutable. Package installations are primarily done through Flatpak, AppImage or exported via Distrobox.
Is... Is that a garbage bag vest?