Their rate of growth underperformed
to their expectations
If you read the article, they still had 37% year over year growth, and already exceed expectations the year prior by 15% (they set a goal of 71% and went up 86%)
If you do the math based off their reported 18million number, that puts them around 24 million. Jez Corden has claimed that they are around 23million so it's safe to say they at least have over 20 million subscribers
PSNow has around 3.2 million
Stadia has never posted official numbers, but reports have them estimated between 1.6-2.4 million users based off the number of accounts
Apple Arcade is estimated to have around 10 million subscribers
Amazon Luna is still in early access and Netflix is obviously just getting their feet wet
And at this point, Gamepass actually has all of the features the other services have and more outside of Stadia's 4K streaming
They didn't meet their expectations but this is not the L you want it to be