I've thought about this before and honestly I can't come up with many things. Telemedicine in terms of speaking to a doctor over video is already very possible over the connections we have today. Bringing that to a wider audience (say, third world countries) is an interesting possibility, but it also requires bringing 5G to third world countries, so I don't think that's going to happen too quickly.
Aside from that, what does 5G really bring us? The same stuff, only faster. I mean, good, sure. But it's not that inspiring.
https://www.cnet.com/news/5g-could-make-self-driving-cars-sm...
There's also the possibility of much faster speeds even in areas without 5g, since the competition will make 3g speeds a really bad look.
They are great, but some use cases quickly hit their limits
The question is this: if the bandwidth of the pipe is expanded to infinity, does the intelligence inhered in the personal owned device remain, or does it wither away... into a rented, datamined, and preternaturally infrastructurally fragile "the cloud"?
Thus far the evidence seems to suggest that "another wave of smartphone and IoT innovation" will fully and finally turn personal devices into dumb terminals administered according to the whim of the Great IBM in the Sky.