That's because
this same Taptic Engine is also responsible for generating unique vibratory feedbacks when you perform a 3D Touch gesture.
Not exact matches
The home button will somehow keep the Touch ID while at the
same time work hand - in - hand with a new
Taptic Engine, thus giving back precise feedback with each press.
This is achieved through Apple's
Taptic Engine, which can effectively recreate a number of sensations, but what's interesting is that the home button doesn't actually need this feature to work — you could use the home button more - or-less the
same without receiving physical feedback.