The important thing is how much more/less difficult is this than spoofing a fingerprint. If it is significantly harder, I still see it as a win for samsung's security.
Spoofing this eye is significantly easier than spoofing a fingerprint, because modern fingerprint technology detect if a fingerprint is "alive" by looking at sweat pores, pulse, veins under the skin and other features of a living finger.
Well, maybe. Usually flagship phones gets the best (most expensive) chips. Budget phones gets knock-offs.
It depends on which fingerprint hw/sw the phone is using. There are about 4 large players in the phone fingerprint chip space that have 90 percent of the market.
Fingerprinting is heavily patented so all four vendors have their pros and cons.
A few dozen small players competing about 10 percent of the market. They probably don't do much of it.