Sure but how would that work for Stadia?
That's beside the point, though—my reply, it's parent and it's grandparent were discussing Google products generally, not Stadia specifically.
[0] I realize that Takeout doesn't support Stadia. Though, for two different Stadia titles (Destiny 2's "cross-play" and NBA2K20's "MyPlayer"), I was prompted to log into a publisher account where my data could be linked/stored or something.
Legally or ethically?