I think the best use case I’ve seen for nfc tags are periodic reminder reset. Place a nfc tag near your filter register then when you change your hvac filter, scanning the tag records the date which can then be used to send notifications when it’s time to change the filters again.
I set up two tags that trigger the Bedtime routine and taped one to the side of my wife and I's bedside tables. I much prefer scanning the tag over bothering with my phone or yelling at Google (until I give up and do it on my phone anyways).
I also set up a few medication reminder tags for my wife. Reminder triggers once an hour until she taps the tag on the pill bottle. Very handy with medications on different schedules.
The spouse acceptance factor is huge. Nothing for her to remember.
I haven't tried HA with NFC tags yet, but if I tap an NFC tag with my phone, it'll show a list of app that can be launched to handle the tag. The phone need to be unlocked though.
HA handles them really well actually. You can flash them directly from the HA app, and as long as NFC is turned on on the phone, you can just scan them and execute whatever automation they're tied to without opening the app. You can buy a 50 pack for like $15 on amazon/aliexpress.
Also if you have a 3D printer, you can slip them into your prints while printing and have them fully sealed inside the object (I have a giant 3D printed house key that has our wifi login embedded in it)