Why does my subaru (cvt) rev so much?

Hello all.

So Ive got a 2016 subaru levorg cvt. I assume (probably incorrectly) that all newish subaru cvts behave more or less the same.

Now to my reflection: The gearbox works excellent while at decent speeds but when taking off or reversing, its really sensitive and its easy to overrev (as in over say 4000rpm when I give say 30% pedal thrust or so, and way off if I give more). The sensation is similar to a low geared small sportscar like a miata/mx-5 in gear 1.

Why do they do that? And why do they overrev beyond the ideal powerband at all (except at high speeds of course, when the gearing is at the limit)?

Its not that its really a problem, I just dont understand it. Is it a technical limitation, or is it calibrated to have that feel?