TLDR, most businesses would prefer to kick this can down the road for as long as possible.
What attitude are you referring to? Do you mean banks and stores trying to get more pennies instead of rounding? It’s going to last for a while. No one wants to be the first to run out of pennies. Or, more specifically, no one wants to be the first to start rounding. However they choose to do it, a good chunk of people will feel that it’s the ‘wrong’ way. I expect the first handful of business that start doing it will see arguments erupting on their social media pages. And those arguments are going to involve accusations of the store stealing from them or ripping them off. Being told they’re rounding the wrong way or otherwise incorrectly. People will be mad that they have to pay more if they use a credit card. SNAP-paying customers will threaten to report the business if they have to pay more than cash paying customers. People that don’t support SNAP will threaten to report the business if SNAP-paying customers pay less than them.
As I mentioned above, I have quite a few extra pennies on hand at my business because I don’t want to be first one in my area to start rounding. I don’t want to be on the wrong side of that argument. I’d rather, at the very least, take into consideration how the general public thinks this should work.
Also consider the public-facing employee that has to, well, face the public. For anyone that’s run a cash register in a retail environment you can understand what these cashiers are about to deal with. People treat cashiers like absolute shit. I can’t tell you how many times I’ve had a cashier walk away from the register in tears because of how a customer treated them. This transition to rounding isn’t going to be fun for them. They’re about to deal with a lot of angry customers. Like retail businesses, the longer they have pennies on hand, the longer they can put off having to deal with this.
WRT to bank tellers, I have to assume banks really can’t be rounding anything so they’ll likely still deal in exact numbers (not exact change), but it’ll be more complicated. For example, if I want to cash a check for $100.03, I assume I’ll either take 2 cents out of that account or deposit 3 cents into it. Not a big deal, but an extra step and could get you backed into a corner if you have an account that limits the number of transactions you can make.
And, having said all that, remember that the general public, as a whole, isn’t terribly smart. I can almost guarantee that even if a store rounds their credit card, SNAP and cash transactions in exactly the same manner and always in favor of the customer, some people will still find a way to piss and moan about it. Either because they don’t understand it, they understand it but don’t like it or because, and these are often the worst people, they’re the type of person that seemingly has to complain about everything all the time and they can get a lot of mileage out of something like this.