With makers chasing ever increasing screen to body ratios for their flagships, there's just no room for the front-mounted fingerprint scanner of yesteryear. Where should it move though - under the screen or round the back - Rossen and George discuss. Ro: "The in-display fingerprint is the future." If it were up to me, I would have kept the fingerprint reader on the front on modern phones, but the trend of bezel-less displays is driving the fingerprints to the back of the device. The chin can no longer house them. But don't get me wrong - I enjoy those full-screen...
Source: https://www.gsmarena.com/sunday_debate_indisplay_vs_rearmounted_fingerprint_scanner-news-32110.php