Seriously.
As an achievement hunter myself, I really think this needs to happen on Stadia. It may seem crazy stupid, but under achievements, there should be sub-catagories for single and multiplayer because multiplayer achievements are sometimes going to be completely impossible on Stadia over time. Some of these games may never see 100% achievements.
No other platform does this. It needs to happen.
Please Stadia team. PLEASE. Be the first, pioneer it. Start an achievement revolution.