Seems like avoiding context switching and all the overhead associated would make a big difference when pretty much everything in cache is critical data.

It’s not. Like the commenter above said: It’s a fraction of the task at hand. Especially when you design the rest of the system to run only if necessary. Context Switches are what? like 50 CPU Cycles? Store Registers, Store TCB, Load other TCB and load other register states jump back to PC. Maybe some other OS Shenanigans, but that’s basically it.

Now Imagine complex calculations on a 25-Dimensional Matrix.