This seems to be the antithesis of the lesson taught in Rich Dad Poor Dad. Stuff is a liability. Even in "owning" it you're still beholden to it. You have to maintain it, store it, protect it, make sure nobody injures themselves with it and sues you. You don't own it, it owns you. Rental, in many areas, is an improvement. Own the couple things that matter to you, rent the rest.

Perhaps it's not so much that Americans own less stuff, but rather the supply of stuff has grown so much that we became overwhelmed with too much ownership and have resorted to rents on more and more of those items by percentage.

Cellphones are an interesting side point, as they don't fully fit into either classification (own or rent). They kind of take on the worst of both. In fact, perhaps there's a market for a phone that's more purely "rent". Given the state of technology and the speed of change, I don't know if there's any real market for a purely "own" phone, unless it's like an ultra-secure dumb phone, in which case yeah there's probably a market for that too.