Pretty much any time you have an open port accepting of wireless data, it should be encrypted, especially when that port is on a device with a cpu. In other words, there are no wireless data transmission applications that don't need encryption other than broadcasting.
I can think of one big case: Many NFC tags are used as QR codes. Encrypting this doesn't really get you anything, since it's public information that's being broadcast freely to anyone anyway.
On the flip side, adding the extra hardware to a tag to support encryption has a non-trivial cost. (NFC tags are limited by both storage space and power.) If you're doing mass production of tags, that cost adds up very quickly.
I'd reason that QR codes are a form of broadcasting. encryption can be done on modern chips with specialized hardware at negligible latency costs. chips that have ops for encryption have been around for over a decade now.
