He didn't mention some benefits...
Cash can get your car out of impound... at least in my area credit is still not accepted
You can get deals if you pay cash... I recently went to florida and could rent beach chairs and umbrellas at the ocean. I told the guy what I wanted, and offered to pay 20% less then posted price with cash (and multiple orders too). We agreed to an amount at 15% less then "msrp" lol. You would be surprised how many places will cut a deal if you offer straight cash, heck some gas stations give an automatic discount on gas if you pay cash (in my area).
Some negatives...
He forgot to mention that with electronic, well at least main stream, you are giving information away. Target uses credit card sales and their POS system to determine which customers are pregnant so they can send coupons for related items. Not terrible but if you are concerned about that aspect... well there it is. Back in the day, businesses would at least offer a vacation give away to get your personal info, now its free for them.
You get an account mix up or stolen card and you are hosed for a bit. Cash, at least if done right can limit exposure to a number of things. Though you could open multiple accounts/cards etc too.
Your wife can find out if you went to a strip club and the last time I went the girls didn't have square readers in their crack for tips.
lol he has a point generally. I will freely admit that I rarely carry cash, unless I am traveling or expecting to barter on serious items.