I'm not sure that necessarily explains the need for single-use NFC tickets, though. There could be a more durable serial-use or permanent card with NFC that regular commuters could buy, and if those commuters are the vast majority of rush hour passengers, it might not be such a problem if single-use tickets had a slightly slower system.
Of course that'd mean having two recognition mechanisms, so the operator might opt for NFC and chips for single-use tickets anyway to make the system simpler. But somehow having single-use tickets with chips on them does seem wasteful to me.
We have those, with two recognition systems. The system the article describes is for the low count, disposable fares (a few tickets or a 3 day pass). Most people in Montreal have a chip card (the OPUS) which is reusable (and 5$ to buy).
The OPUS is also super interesting because it's a stored value card that holds the tokens on the card as opposed to a simple ID. The system was developed when cellular connectivity was still spotty, so they needed a card that would work on buses without internet access. It's pretty bad from a UX point of view though: you can only store a few different kind of fares, you can't recharge the card online (until recently you had to go to a terminal to do it, now there is a NFC phone app), you can't declare a card stolen, etc.
Ok, that makes sense then. I know that systems with non-disposable cards exist, and we also have one in the Helsinki metro area. I think our present system assumes continuous connectivity, though. Now and then you see buses with the terminal in a non-functioning state. Ends up being a free ride. (You can also buy unlimited travel within a given zone for x days at a time, which is what those who use public transit daily usually get.)
I think most people nowadays use a phone app rather than the card, though. But we also don't have gates at stations, and it's more of a trust and ticket inspections system similarly to what someone said about Norway.
Japan has the Pasmo system which is weird in that it's actually more like a prepaid debit-style card that you can use not only on most public transit but also as a payment method at some shops etc. You can charge it using teller machines at stations. I can't remember the details, though.
But why are there disposable tickets at all? Even if you're just visiting, buy a transit card and use it, then get your deposit back when you leave (or keep it as a keepsake).
The idea that you still need single-use tickets for any use-case once you have a working transit card is just bonkers. You don't, stop making them.
Some people are passing through and only stay at a city overnight, or are just making a day trip, and getting a card and returning it for a deposit might be a hassle. You might be visiting multiple cities within a brief period, each with a different system and different card, and getting and returning a card at each sounds cumbersome. More or less the same if you occasionally visit different cities in your country or area but not often enough that you'd want to keep cards for a bunch of cities. A local might forget their card and need to make a single trip.
I can see lots of use cases for single-use tickets. All of them are technically possible to cover with a non-disposable card, of course, but that doesn't mean single-use isn't more convenient in some of them.
Nowadays phone apps might also be an option, but that can hardly be the only way of paying for public transit.
Taipei has single use NFC tokens that people can buy, but they are non-disposable. Instead, they are coin shaped, and are deposited in the ticket machine at the end of the trip so they can be re-used.
Of course that'd mean having two recognition mechanisms, so the operator might opt for NFC and chips for single-use tickets anyway to make the system simpler. But somehow having single-use tickets with chips on them does seem wasteful to me.