The way users share their addresses is by copy/pasting it or via QR codes. Now that every phone has an NFC chip in, isn’t possible to use this to share the address / initiate a payment?
Just getting the phone closer to another one would make it easier. The experience would also be much more similar to conventional phone payment methods (Apple wallet / Google wallet)
Is there a reason why this doesn’t seem to exist in wallet apps?
Personally, I disable proximity sharing because it’s frightening but I’m just kind of like that ya know, I know too much about radio 
Is it a popular thing?
I do agree with you… I thought it would have to be coupled with faceID or similar (I have an iPhone …) Again, the same way Apple wallet works
Apple does not expose the NFC api for sender data out. It’s only for Apple Pay.
OK, so that explains it I guess…
What about Android?
This is a great idea and I’m not aware of anyone in the cryptocurrency space utilizing this.
I’ve won a hackathon where my team built a “Tap & Go” proof-of-concept mobile self-checkout store utilizing NFC tags and iPhone/Android phones to read the item-price metadata and open a deep link to the payment page. This is totally possible to integrate with the checkout flow in a Zcash mobile wallet.
https://developer.apple.com/documentation/corenfc/building_an_nfc_tag-reader_app
Sounds good!
So it is actually possible to implement this in a wallet?
Just having to get two phones closer to each other to share an address or initiate a transaction?
Not between any two phones. A phone and a tag: OK. Android supports HCE but it’s complicated and iOS doesn’t allow apps to use it anyway.
A very popular payment app here just introduced an alternative to the usual QR codes by using bluetooth. the principle is the same:
The vendor makes a payment request and the buyer just needs to open the app (have bluetooth activated) and get his phone close to the other. The buyer then sees on his screen the request for payment, and just has to slide a button to confirm and do the transaction.
That was considered but in the end, I think Bluetooth isn’t secure / private enough. Besides it’s not more convenient than QR codes.