It's easier to make a political philosophy by leaving out part of the equation. They do the same thing in relativity and quantum mechanics and that works quite well. The problem with Ayn Rand is not what she says but what she leaves out. If everyone was as good as her a Utopia could perhaps exist, the same as the communist Utopia which I think is the polar opposite of what she is talking about.
However once you accept that you need to control people for their evil greedy tendencies then you have either self regulation or outside regulation. These people can't control themselves so then you outside regulations from a government or deciding body and that starts to leave libertarianism behind.
I think the only system that works is a mix of socialism and capitalism. The population is about half left and half right wing and domination of any one side will never be accepted by the core of the opposite wing. With a balance people work together, if one side predominates the other has a kind of resistance to it that cancels out any hypothetical benefits. You can get rid of social security and then spend more than that on police protecting the assets of the rich. You can get rid of capitalism and take away people's right to privacy so you can watch for signs of it breaking out. The only successful systems in history keep a balance between all views.
That doesn't suit some people because their politicial views are self referential. They base their views for example on capitalism as a premise and it seems to explain most things except for leaving out some pesky details. The same can be said for socialism. When you put them together everything is explained.
Fools and knaves works pretty well as a simplification of this. Some people aren't very foolish and others aren't really knaves most of the time. They have a lot of trouble making money off the educated not so foolish. Ayn Rand is talking about the people who are sharp in business but basically honest but this is an indistinct border, where ripping someone off becomes doing a good deal at someone's expense. If the ripping off is not too great then a system like hers can work even without socialism, if there are too many crooks then the poor get gouged too much, become resentful, and then socialism develops as a protective response.
Likewise a society of the not too foolish can do ok under socialism even without the brilliant and talented. Most things get done but not as well. Perhap without competition progress is slower, that's all. If people are too foolish then the economy fails through ineptitude.
Getting the right mix is important. If either side wants to go off and make their extreme system work then let them do it and show the world. The objectivists haven't done that yet so they can't offer any proof.
In fact though human history this balance has been rediscovered in each village and tribe long before economic theory. Most societies have evolved with a safety net of some kind and restrictions on the rich even if they are just the local big farm owner dominating which is essentially feudalism.