We see this again and again. The cynic in me sees Stadia as yet another internal promotion scheme, masquerading as a product.
I doubt this will ever change. The internal momentum of the company culture will make it so. What does it mean for investors? Google has enough money they can just buy their way into markets indefinitely. It will probably keep them going, but I don't expect huge growth. I'd probably be putting my money into other stocks if I had to choose. I honestly don't think people would miss Google much if it was gone.
This goes well beyond Stadia - Google has an air of institutional contempt for humans, especially humans who aren't inside Google. Dealing with humans who are struggling with getting bounced by "the algorithm" is something they simply aren't interested in.