I'm going to treat this as a genuine question.
The best thing you can do is announce how Stadia has worked for you in a public setting. Show others that people are having a good time with Stadia!
100% Go join Reddit and find a gaming channel to preach in.
Convince your friends to TRY it (free to try). Or if you don't have friends, convince your mom to try it out (that's my sitch).
And give feedback whenever and where ever possible
You can ‘send an invite’ from the Stadia site to friends too. I’ve sent one to so many people and told so many how awesome it actually is (even my electrician) but so far only one person has joined,
Stadia is epic. It will be the future, just need to give it time to build momentum...
@Keebeees get friends and people to try it, in their hands. Im sure the first thing we all did with Stadia was say 'okay, let's give this a try', that element of cynicism rattling around in our heads.
This was, for most of us, overtaken by that experience of wow and excitement. Stadia works...
We are trying to pass the second emotion onto people still struggling with the first. Getting people to try it is a major, major hurdle.