There are a million usages por small pieces of data like names, phones, etc. Not everybody would use them but for those who do removing them would be a mistake. If I want to identify myself as a merchant in wallets that allow manageData then I'd set my name in a data field and special wallets would easily show the name in the contacts list without need for typing them. That's just one case. Time ago we were discussing defining inflation percentages for charity in the data fields, so use cases are aplenty, the fact that we don't see them doesn't mean they don't exist.
I vote for keeping them.