As usual I get quite hopeful when I hear about a new operating system. We so absolutely need paths to move away from what we have today. I didn't even know what "mixed reality operating system" was so that made me hopeful. May include some nifty quantum processing. Alas, it is just stuff built on top of Android, which is built on top of the Linux kernel. Perhaps "Meta Horizon SDK for Android" would be a better label?…
I was amused and interested when I found out that HaikuOS is not Linux, nor even the Linux Kernel, but a reimplementation of BeOS (concepts mostly) on the NewOS kernel. I've been dwelling in some nostalgia recently and miss some of the earlier days when everything wasn't so homogenous. This is all rose-colored glasses though, as I don't miss when everything was also extremely incompatible. And slow. And expensive.
You are not alone in this. I see announcements like this one from Meta and others like Oxide - companies out there having a swing in a different direction and it makes me glad that there are people out there thinking outside the monoculture that computing feels like it's become sometimes.
Sure, standardisation has been good in some respects, but I feel like the incentive to really innovate (as opposed to incrementally improve) in the operating system and compute space has really dried up.