my point is that Linux is dragging a lot of baggage around in the form of support for old APIs and so on.
Eventually, someone will create a new OS that does a way with the accumulated baggage, and as a result is able to do things more efficently. It will probably start with some smart person putting together something for their own use 'not intended to be big and professional', just like Linux was.
It's foolish to think that Linux is the ultimate OS (or kernel).
The kernel development model (and rate of adoption in accepting changes) should push this point out a long ways, but eventually the pile of cruft will accumulate to the point that something new (or a fork that throws away a lot of compatibility with the existing kernel) will take over.