[ykumar6]

Yes, I 100% understand that point. But I repeat what I'm saying, this isn't a concern for most developers and most software companies. They don't care how a page table is written. They don't care about optimizing that.

Every standard or abstraction can be unbundled into multiple standards or abstractions. But at the end of the day, what wins is something that's simplest to the operator

[vezzy-fnord]

You're not really contradicting anything, you're just making an argument from personal incredulity. People do care, you may not. Else the Linux kernel would have had a fraction of its manpower and no one would want to introduce userspace page fault handling (just recently userfaultfd(2) went in from a KVM optimization effort) or use userland TCP/IP.