Dolphin emulator is officially coming to Steam
The emulator is still not available though, despite the store page for it existing, as the store front only details the current release date for the emulator, which only says "Q2 2023". The dev team mentions that this is due to how Steam works currently, but surely the emulator shouldn't be that far off from the official release.
It is currently unknown what features will the Dolphin emulator on Steam will include, as it wasn't mentioned in the post, though many users would like to see save cloud storage possible through the Steam app. Steam Deck accessiblity will most likely be one of the features as well, but we have yet to see.
Source
Dolphin's Store Page on Steam