> Most importantly, why would users care about decentralized vs centralized?

Probably few, except those actively searching for it. And, especially with decentralisation, the inevitable outcome of being too popular is that it starts to become centralised again, to make things easier.

Besides that, I thought for a moment about Apple's tech. If you and a friend have an iPhone and you're both trying to connect to the same network (and have each other in your contacts, I think), iOS will allow you to automatically share the credentials and connect the other phone too.

I reckon that you'd see a lot of value in that kind of device integration, which is essentially peer-to-peer.