If you're running a business dealing with cash has a cost. You need a till, you need to keep track of what goes in and out, and at the end of the week you need to take the cash and deposit it in the bank. This is all overhead, and it's much more efficient when all of that is done automatically by Square or whatever POS system you choose.
High traffic services such as public transportation or supermarket shopping will bottleneck with cash. Can you imagine if everyone that wanted to use the Tube in London needed to pay in cash? You'd have a queue that starts in the Cotswolds. Alternatives (like in Berlin) are to make sure everyone buys their train ticket beforehand, and then use ticket inspectors to make sure people travelling have paid - this will lose the transport operator money and make it harder to optimise services based on real-time demand.
We aren't moving towards cashlessness because of some government conspiracy to track us everywhere (governments can do that easily enough via the Internet anyway), it's because it's cheaper, faster, and more convenient for everyone participating in the economy.
Finally, I don't think the dystopia painted in the article is realistic in western countries. The flow of money in the economy is primarily controlled by the private banking sector, with oversight from a central bank (which is public-private hybrid). Transactions can be handled directly from bank to bank, or via a payment processor like VISA or Mastercard. These are all for-profit corporations, and they comply with governments for requests for data, but governments do not have any direct intervention in individual transactions, nor are there rules that could be applied to block transactions on a granular level.
TL;DR we're going cashless because it's objectively better.