And honestly they're not that convenient. The Touch ID in my iPhone 8+ rejects my print at least a dozen times a day. On some days it rejects it many times in a row, forcing me to key in my unlock code.
Research like this, while ostensibly threatening an increase in false positives (due to unauthorized use of fake prints), will in all likelihood cause vendors to tighten the confidence interval, leading to greatly increased false negatives. If my print is recognized less than half the time I'm just going to disable the feature.