This seems par for the course in computer architecture, and probably computer systems in general.
Part of it seems to be that technological improvements (such as better silicon and faster compute/storage/communication as well as more input data) can enable formerly impractical ideas to scale up/out and become useful.
Another part is that the performance and power wall has forced CPU designers to think about other ways to improve CPUs, such as improving security and reliability. Maybe the market will finally be willing to trade off some cost and speed for better security and reliability.
Lastly, software which used to be impractical or overly expensive because of resource usage can often run easily on modern hardware.
Most likely the hardware constraints and economics.
Burroughs was one of the first systems with it, the Lisp and Ada Machines, Xerox Workstations, IBM mainframes, ETHZ systems, among others, all of them rather expensive, or niche, when compared with what became regular consumer hardware.
The failure of Intel's APX32 project probably did not help as well.
I find it's often the case exciting new tech turns out to have its fundamental principles described in a paper from the 60s or 70s ;)