There are some phones to be released later this year - as well as some that already have been - with in- or under-display fingerprint (FP) scanners. This technology is based on optical (or light) sensors that act to construct a 2D FP model in order to learn, store and authenticate different prints. However, it seems that next year's versions will improve on this method.
https://www.notebookcheck.net/2019-s-in-display-fingerprint-reader-may-be-considerably-better-than-2018-s.338096.0.html
This isn't gonna immediately translate into sales, most consumers can't tell one from another, they only notice the position.