Google has taken a stepmto this direction with Fuchsia. To replace the Linux kernel under Android/ChromeOS and maybe later the servers. But it will be a massive undertaking due to massive sunken cost in the UNIX legacy.
Yes, but if no one ever spends the money, it will never change.
The main reason why alternatives failed so far it wasn't for lack of technical capabilities, rather companies not willing to put the money in for the long road it takes to reboot everything.
At least the majority of userspace applications are moving into the right direction, specially those being deployed on cloud environments on top of orchestrated runtimes, or the mobile phone apps.
Linux isn't Unix: commercial Unix already got obliterated by Linux (and the dotcom bubble, Itanium). Completely different development model, vastly different capabilities.
The main reason why alternatives failed so far it wasn't for lack of technical capabilities, rather companies not willing to put the money in for the long road it takes to reboot everything.
At least the majority of userspace applications are moving into the right direction, specially those being deployed on cloud environments on top of orchestrated runtimes, or the mobile phone apps.