A good question to pose and ponder indeed.
Ownership was a social concept we developed to avoid having to fight for things every time two persons needed a scarce resource. Doesn't work all the time, but avoiding the injuries of even one fight in 10 is still a worthwhile gain.
In a society where most things are plentiful and we have no fear for our survival a concept like ownership may seem outdated and even oppressive, a part of a conspiracy to trap up into needing thing we don't really need for our happiness.
While it is beneficial to understand what resources are really essential for our lives and what things are superfluous, take into consideration that owning something is what allows enterprise to happen. For something to be built upon it must remain available to the builder and must be safeguarded from those that would sacrifice the long term gains for the immediate gain.