Yeah, I pretty much disagree with the author when it comes to something like inputing your birthday. For something like hotel stays or airplane tickets, it does

Yeah, I pretty much disagree with the author when it comes to something like inputing your birthday. For something like hotel stays or airplane tickets, it does make sense to show a full calendar to give a sense of the range between two dates, but for inputing a birthday I'll take the "9 taps" required to fill out the three fields on mobile. I think it's going to end up faster than alternating between tapping to select a field and typing to enter the value.