That's easy. It's not primarily about ownership. It's about the availability of resources and capabilities. And lacking a better, more reliable, more trustworthy alternatives, i.e. it's the best we got, I would cripple or handicap myself therefore blocking my ability to contribute in the way I can meaningfully contribute.

So, yeah, this is a somewhat shallow perspective. This would've been a lot more meaningful in Aurelius's time. I get his ideas. I just think it's a simplification that isn't always reachable/feasible in our society.