De-coupling of hardware and software mainly. All kinds of 3rd parties writing drivers for the trackpad for an OS they don't have control over.

I've heard the Microsoft Surface is very good.

Most Windows PCs which ship with precision drivers and an oversized glass trackpad feel 90% as good as the MacBooks. The Surface line and the new Razer Blade 15 are two examples.

The precision drivers are key. Many manufacturers still haven't adopted them, and they are the main reason why Windows trackpads still get a bad rep.

I like my XPS 13 trackpad :) The mac ones seems too big, suspect it would be in the way and hamper the keyboard. (I haven't used a the newer Mac models enough to be certain). Dells works great on Linux (Arch + KDE)

Surface's trackpad is as good as Mac's even though all other parts of experience is trash.

However, now Mac has this force touchpad which you don't really press, so it recognises all of the presses with no respect to where you do it. Nobody has anything like this and I must tell you that one gets used to it reaaaaaaly quick.