>>8usually environments are optimized for specialized uses as static offsets into specialized base pointers or object pointers or class variable pointers held in registers, or resolved to static variables, or even different optimized versions of slots - each case optimized to a very specific implementation of that.
But Kernel doesn't have pre-built specialized implementations of environments, environments are created in user code and can be any sort of spaghetti the user wants. And in computing there isn't ONE implementation of objects or modules or any of those things - it's just important the the compiler know ahead of time what model is used so that it can optimize to it.
So it would be very hard indeed for a Kernel system to analyze a users code, figure out which kinds of patterns of environment inheritance the user has created over and over, find the most efficient flattened model of it, and put that in the code.
Kernel very much breaks the mapping from user code to machine code that was the original purpose of high level languages.