I have some cash since March, coins and notes that I have little use for since then.
Signs at shops, on windows and as soon as you go to a restaurant you are told you have to pay by credit or debit card.
The only use I have had for coins and notes is for my haircut place that only accept s cash and buying/selling items on Craigslist.
The pros of a cashless society are:
Convenience - coins are heavy and annoying. Cashless means you don't have to count money to purchase, tap or chip and pin and go.
Speed (if contactless) - spend less time queueing for purchases if everyone is using contactless payments.
Security -provided your cards aren't contactless if you lose your card you won't lose money if you cancel it straight away.
Electronic records- it's useful to know what and where your money is going so that you can budget well.
Cons:
Banks and government have more control. If there is a run on the banks good luck getting cash if you need it.
Banks and governments have more accurate information about where you are, where you go etc. Based on your spending someone could predict exactly where you are on certain days and times and all it takes is one person with a grudge or financial incentive to ruin lives to rob or assault you if they know your location.
This is true to a certain extent with ATM withdrawals but if you could withdraw cash twice a month for your spending then banks wouldn't be able to say you were at the pharmacy at 2pm for example.
Taxation- good luck trying to run a business that only accepts cash if all your competitors only accept cards. Who should the tax man randomly audit, someone with an electronic trail or someone without one?
Tax man is likely to have more discovery for businesses that don't accept cards.
If you under declare income and everything runs through your bank account you are almost certainly going to be caught so therefore you almost certainly will try to file taxes accurately. From a government revenue point of view they will get more out of coming down hard on cash only businesses.
Further on a business side, if few people carry cash and you don't accept cards your customers will shift to competitors who accept cards out of necessity and/or convenience. Your hand will likely be forced sooner or later.
Security - if you lose a wallet of cash the loss is limited but if you lose a contactless card or a credit card you could lose a significantly higher amount before realising the loss or theft. Also cancelling contactless cards takes several days to actually cancel so someone can buy stuff without a pin in the meantime using your card.
Reliance on internet and electricity - Cash is king if there are electricity or internet blackouts. Chip and pin machines may have long battery lives but without a stable internet many won't work.
I've been in situations where shops just close when internet goes down or tell you to come back with cash. But if power is gone ATMs can be down too. Back to trading tulips for sandwiches.