I actually think that there are a couple of solid examples of this:
* Console/PC videogames: people wanna play God of War on their bus ride, as evidenced by the massive success of the Switch and the growing excitement for the Steam Deck
* High-quality video calling: latency and bandwidth increases in 5G are both huge for the experience of FaceTime/Skype/Discord/etc.
* VR/AR: again, applications that are seriously harmed by both latency and bandwidth, and ones that have many concrete, business-value use cases in a mobile / non-living-room setting.
and my "dark horse" candidate:
* Machine learning applications: any "AI"-powered product or service has a quality that is pretty directly proportional to the amount of iterations it can perform. Self-driving cars have the capacity to gather gigabytes per second of environmental data; the ability to stream this data back to a central e.g. Tesla datacenter, rather than just doing procession onboard, confers a pretty serious increase to model quality.