Google doesn't work like this.
People can almost autonomously spawn up small projects.
If it looks promising they keep getting more resources until it either has explosive growth and profits or someone higher in the chain thinks there isn't a current viable path for THAT version of the project to profitablity.
Google might believe in XR and keep funding these small projects, but if none of them display evidence that that particular approach is going to be huge, then they move on.
It's not top down.
Sundar doesn't say, we need more XR. Team, go find me the most promising options, and then we'll fund it to the moon. And then a month later he gets bored and says, no, never mind, kill that. Let's chase another hype bubble. Only to then months later come back and say, team, we need more XR!
This may be the case, but everything eventually gets compared to the ad business, and the projected financials, no matter how optimistic, look terrible. Then the team leading the initiative wises up and drops it, gets tasked with something else or frustrated and those people leave.
Right, that's the job of some random PM who will launch a half-baked XR project that overlaps with a nearly identical XR project down the hall, which will compete with its fellow Google project/product in the marketplace and confuse customers before getting killed within 18 months of launch. See also Google Wallet and Google Wallet (yes), Allo and Duo and GChat and Hangouts, and so on.
... wat? Are you suggesting Google has two different services both called Google wallet?
Not one, not two, but three different things called Google wallet, and four different things called Google Pay, one of which was formerly called Google wallet and one of which went on to be called Google wallet.
How is this real?
I let my password manager handle it now.
Yeah, it was dumb having your app change names and slightly looks, but materially, little changed.
Anything on that scale Apple/Meta bets on is definitely brought up at the highest executive level and there has to be some thought going on what the response would be if any.
Disclaimer: I'm willing to believe that I just had less swing/power than you did at Google (or am not skilled at getting those things alight), but the idea that this was spun up "autonomously" (organically/grass roots) seems pretty far fetched.
tldr; Most things were delegated hierarchically from my experience.
It would also be ridiculous for you to even try.
But you can spin up smaller things, and L7+ can start major projects if they want to risk their career.
And that's how most of the non-massive initiatives have worked.
Massive initiatives like Stadia, Cloud, Maps, Social, Play, and Gemini are atypical at Google considering the thousands of smaller projects that have launched, maybe tens of thousands considering internal projects.
Even most of those project decisions aren't happening at the C level.
I think the obvious notable exception is Android, which is not going anywhere and which now has a fairly delightful development experience with Kotlin and Compose.
Kotlin folks have prevented Java support on purpose, only to be forced to update Java support, as Android slowly started to be frozen in time, thus Kotlin losing one of its selling points, Java compatibility, with everyone on JVM world moving beyond Java 8.
Go check any recent Android conference, and most likely there will be a few talks related to Compose performance and gotchas.
I guess they know there will always be someone else to fill the void, but certainly by the time of GearVR and later Stadia the whole games industry was wise to allowing any of FAANG near the crown jewels, which is a major factor in why software support for VR has been so unenthusiastic. This was not helped by Oculus hiring the old Scaleform execs who had just pissed off half the universe.