The other factor is that people who use tickets regularly would use the rechargeable plastic cards, rather than the disposable tickets, so the amount of waste is reduced.
It does add significant costs to the transport system. Single-use NFC cards must cost at least a few cents to produce and dispense, which adds up when you’re talking about hundreds of thousands or millions of rides every day.
Even reusable NFC cards are costly in terms of providing all the infrastructure to support them: software, servers, enough top-up machines in stations to handle peak demand, commissions to retailers selling the cards, extra staff to deal with customer support, delays and congestion caused by top-up/ticketing queues, etc.
That’s one reason London’s TfL has been pushing everyone to just use their bank-issued contactless credit/debit cards (or NFC-enabled phones) for years now.
It’s also more convenient, of course, to never have to worry about your balance or recharging the card.
Unfortunately the days where you could ride the buses for free around the whole Heathrow area are gone, however.
Many transit agencies do explicitly incentivize reuse, e.g. by offering cheaper fares using a reloadable contactless card and often charging a deposit for that card.
Even then, many of these systems have been struggling due to the IC shortage, given the low margins these single-use tickets have to operate on. In some Asian countries, including Japan and Malaysia, it was tricky to get a new transit card for several months or even years, even though there is a deposit charge.
A ticket needs to be printed anyways, the single use ticket with chip does not come from thin air.
The NFC doesn't need to be printed. It just needs to be dispensed.
My city went from printed paper tickets, that didn't even need to be scanned, to contactless fare system with paper NFC tickets. It saves money having simpler and less used ticket machines. It helps that most people use contactless credit card or fare card. They really should have more signs that can tap phone or credit card cause I suspect tourists think they need to buy ticket.
Magstripes tend to work not so well when you have the ticket in your pocket for a couple days, printed codes involve people futzing with cameras. You can use a sort of card ingestion system to line up a QR code or the like... but those things are complicated and break down a lot! You end up needing staff to constantly be opening it and unclogging it. This works alright if you have like 6 turnstiles, less so when you have 2 or 3.
Obviously you can work with those models anyways, and plenty of transportation networks do! But if your rush hour involves moving a million+ people, you really do need this stuff to go fast.
How very true... SWIPE CARD AGAIN AT THIS TURNSTILE in glowing turqouise-ish dot matrix letters will be forever etched into my brain long after the Metrocard is finally gone.