Interesting perspective. So, if I'm understanding you correctly, the pitch here would be:

1. Paycheck DD → straight to savings

2. "Spending money" for in-person transactions → transfer periodically to checking

3. Use debit card to spend from checking.

That's an interesting idea. Actually what is intriguing to me is another angle: I'd still never consider spending with debit. But my problem is that it's essentially impossible to get an ATM card that isn't a debit card anymore, meaning if I want to be able to use an ATM, I have to carry this stupid card around that would be easy to use to drain my checking account. With your approach, if I can get a savings account that is not linked to a checking account, I could use that as my default place where I pay my rent and credit card bills from. But it's a big if, because a lot of savings accounts have limits on how many withdrawals they can have per month, probably a residue of that regulation that someone else said was recently repealed.

While Regulation D was lifted a few years ago, there are often still restrictions to the number of withdrawals one can do from a lot of savings accounts.