There's not nearly as much scarcity as we're led to believe. I did some internet research a while back and concluded that roughly 2/3 of the food we produce is wasted, according to an average of all the information I could find on the subject. Even if I'm wrong, I know it's enough to support the freeganism movement in excess. People who start feeding themselves by dumpster diving commonly report having more access to food and eating healthier than when they did before, because just so goddamn much perfectly good stuff is thrown away. Hell, Food Not Bombs provides most of its services with freely gathered food and they feed A LOT of people.
Not to mention it wasn't too long ago that the U.S. undertook its megaproject of kicking millions of people out of their homes just so all those shelters could rot empty, especially with banks keeping the majority of those homes off the market to artificially keep up prices.
And imagine how much more we could provide if the majority of our resources (time, energy, raw materials) didn't go towards killing each other, or perpetuating hollow mass consumerism which only exists to appease the hollow lives of servitude of the majority who put all of THEIR resources into providing as much disgusting excess as possible for those at the top.
Yes, providing equally for everyone would require sacrifice for those in, let's say, the wealthiest 10% of the world's population. I know I'm probably in there somewhere. At least I wouldn't be living in guilt as a cog in the machine like I do now. And before you deplore my lack of integrity for not quitting my job and hitting the streets as soon as my conscience nags me, I have a diabetic child. It's not an option for me.
I'm not even suggesting a communist-like equal distribution of resources, either. I'm only saying that it would be much much more equal after this societal structure which requires the vast majority to dedicate their lives to enriching a few is dismantled, and this will not happen as long as any system of property/authority exists, no matter where it falls to the right or the left.