I have a few things to say.
Firstly, it is way too soon to call the visionOS platform a failure. I think everyone knew the first generation would be a tough sell. I've always looked at it as a proof of concept. But the long term vision (pun intended) is to bring the price down and shrink it to a size that's more comfortable. People forget that the first all in one PCs (Lisa, Macintosh) were very slow sellers initially. And were very expensive. I'm not even going to attempt to predict Vision Pro's future, but I think it would be foolish to write it's obituary at this stage.
Second, they're not all going to be hits. Steve Jobs demonstrated that plenty of times. Along with the original Macintosh, the G4 Cube was a tough sell too. As well as the iPod Hi-Fi and buttonless iPod shuffle. These weren't as ambitious as Vision Pro, but they were misses. But overall, I think Tim is allowed one miss out of all the successes he's had.
And third, yes, there were rumors of products Apple was working on that were ultimately delayed or cancelled. But this is nothing new. Apple, as well as every other tech company, has experimented with new ideas and cancelled them behind the scenes. Now is it more embarrassing that Apple announced AirPower publicly and cancelled it? Yes. But I'm old enough to remember Steve Jobs promising over and over again to put a G5 processor in a PowerBook, and he failed on that promise, hence the switch to Intel. And another thing, I think rumors of projects spread like wildfire in today's landscape just because everyone is so connected with the internet and social media. Back in the day, it was a lot easier to contain leaks. I'm sure there were plenty of ideas that we've never even heard about during Steve Jobs' tenure.
Long rant over. TL;DR- Too early to call the visionOS platform a flop, Apple isn't doomed, Tim Cook has done an amazing job operating the company, not every product idea sees the light of day