Layman's take: All of them are afraid of making the system that fulfills the promise nominally, but that lacks some key component or is on hardware that doesn't get adopted, only to have a competitor swoop in, clone that system with the necessary fixes, and essentially do what Apple did with MP3 players and smartphones. They're all trying to establish market dominance BEFORE giving us a reason to use the devices (bass ackwards) - and are even happy to see the market collapse, if it meant that, simply, no one cracked that particular nut.

Apple, Meta, Microsoft like how things are right now. These pushes are much-hyped, but they're made less out of real passion for the promise and more desperation to avoid being left behind.