Apple didn't go their own way one this - they teamed up with the people who know this better than anyone, from Pixar to Epic.

No, they made a minor change to an existing Pixar file format. Pixar who they already had a very cozy relationship with. The whole industry was standardizing onto glTF and Apple couldn't let that stand.

Your assumptions underscore your bias. Perhaps they have bigger dreams then the rest of industry.

Apple stands out from the rest of those industry players by historically having much longer range architectural vision. They have also been investing heavily in their devices for many years to support that vision. The processing power of the typical iPhone outruns average competitor by multiples.

Epic? As far as I can tell, Unreal Engine supports glTF import and does not support USDZ.

Which makes sense, because this is what glTF was designed for.

https://forums.unrealengine.com/development-discussion/conte...

Posting that Epic can import more than one file format does not prove me wrong.

Thankfully, some quotes from Epic Directors can prove me right....

https://uploadvr.com/epic-games-unreal-engine-april/

To quotes the Technical Director from Epic:

“We will increasingly use USD here. Hopefully, we will keep working with Pixar to make it awesome for every use case we can imagine. ”

And,

“The cool thing here is that we don’t need any other separate tools to go from USD to what you’d see on screen with this demo”