I find using cash to pay is quicker than using a card or other device.
I'm starting to find the opposite and sometimes, when paying cash, feel like I'm the old lady with a checkbook that I always complain about.
At the aforementioned Costco for example, I can stick my card in the reader while they're ringing my stuff up. My wallet is already back in my pocket before they ever hand me the receipt. When I pay cash, it's however long it takes them to give me my change, and all too often if I give them two Franklins for say a $140 purchase, they end up having to call a manager for change. And that's at Costco, where they're pushing a lot of people through every hour.
As mentioned in my post above, if going out to breakfast or something, I find it's the opposite, because I just leave cash on the table when the bill arrives and I'm gone. A busy server might take 10 minutes to come back just to get my credit card, let alone bring it back.
Side note from reading the article in the OP: I was very surprised that there are apparently tons of restaurants in NYC that are cash only. In a big city like that, I would have assumed they'd be going to "NO cash" type establishments.
There's a place I go for breakfast whenever I'm fishing in Mammoth, and they're I think the only place there that is cash only. They even put an ATM machine in their lobby for convenience. Yet if you read the Yelp reviews, the biggest complaint about the place is "cash only". I've talked to the owner before and she's conservative/libertarian and has the rule mostly for political reasons, as in, "This is America and cash is still valid". On Yelp everyone thinks she does it to cheat on her taxes.