Yeah, that's what one would believe, right? Well, I was forced to prioritize the research for this because of reasons and did two tests.
1. I checked the largest price-comparison site in my country. They have loads of products, also phones. And they allow searching by properties, including
missing properties. So I searched for mobile phones launched since 2019 that didn't have NFC. Turns out new models are being launched each year without NFC. Also from big brands, so not just weird no-name phones. I mean, Samsung, Motorola, Xiaomi etc - they all have phones without NFC.
2. I also looked in my database. For debugging reasons I save the model number of each of my users. (That has really helped when narrowing down a couple of bugs!) I don't have much other info on their device, but at least I have that. So I made a list with all devices that had been active during 2023, removed duplicates, scrambled the order and took the 100 first. Then I manually looked them up at
https://phonedb.net/ to see if they did support NFC. Out of the 100 models I looked at, 69 did support NFC and 31 did not. That's almost a third of the devices.
Considering all this, I think it's fairly clear we can't assume a user have a mobile with NFC. I welcome thoughts and counteropinions.