[blacklion]

Because different tasks requires different trade-offs and Linux has only one set of trade-offs. You cannot do good universal tool. It is like Leatherman, good enough to fix-up your bike on the side of the road, not so for normal workshop.

You say: reinvent the wheel.

I say: use pickup truck for every task, from farming to racing to commuting moving goods across continent. Is it possible? Of course. Is it good idea? I don't think so.

All cars are the same if you squint enough, wheels, engine, some frame, some controls, which are not very different between even F1 car and 18-wheel truck.