Wonder what stunted adoption of this? High costs, users not liking it b/c privacy, credit cards/tap to pay being a good enough experience already? The handful of times I used this, it was nice.
But have no idea why anyone else would adopt this.
It does seem like a technology that should have a useful niche. Unlike fingerprints you don't leave partial copies of your vein pattern on everything you touch; unlike face recognition it's an explicit act you take so it can be used for attestation-type actions (like paying). It still has all the usual disadvantages and advantages of any other biometric. Perhaps the unique niche isn't big enough to fit a new product into though.