Checks allow for instant transfer of money between two banks, for free. That's what I still use them for.
I am willing to wager your credit union is not paying you 3.5% APY on your checking account. That is, if you had $10,000 in your checking account at the end of the year, and you just left it there, you would not have $10,375 at the end of year.
There is a restriction/surcharge in there that you haven't mentioned.
I wish I could re-finance my mortgage at 3.375% fixed. :(
This is why I don't understand why people keep going back to banks and getting screwed every single time. The bank is there to make money off its customers; the credit union, by definition, is there to make money for its customers.
https://www.kemba.com/checking-savings/checking/get-green-ch...