It takes up as much screen space as the Windows taskbar while doing a fraction as much.
In windows that same screen spaces acts an application launcher / switcher, but also an individual window launcher / switcher, and a clock, utility, and notification space.
Mac smears half of those into a fully separate system bar that takes up even more space.
It's not a mac vs anyone thing, it's not a mac way of doing things, it's not like if they had a better dock the whole OS would have to change or fall apart, it's simply just a badly designed dock / taskbar.