Just an important note is that this re-explosion of debit reward cards (Southwest is doing something too) is because these smaller banks can charge almost credit-like rates (exempt) for debit transactions which will help cover the cost of the miles. Chase could not do that if they offered a UA debit card as they are not exempt whatsoever.

https://staxpayments.com/blog/unders...terchange_Fees

Now, it is true, a number of companies (tax/government payments), etc charge less for debit charges. If customers push these charges heavily into these categories and not enough "normal" spending, expect the card issuers to offer no miles or even less than the .5 rate for such transactions. But the use case for now is to uses these transactions for merchants that don't surcharge as much for debit vs credit which would be all of the government or quasi-government entities. In all other cases, a United Gateway card might be better?