Though Minecraft Java Edition can be downloaded and installed using Mojang's official launcher, the same can be achieved via custom launchers.

Somewhat confusingly, there was an old launcher called 'Minecraft Unified Launcher', which was specifically for Windows 7 and 8 and only launched Java Edition and Minecraft Dungeons.

Minecraft players struggle to play Java Edition with the new Launcher causing log-in difficulties and long download times.

Run Minecraft Java on your Steam Deck with my straightforward step-by-step guide, using Prism Launcher to keep things simple.