It occurs to me that the libertarian dilemma you mention, that the unregulated market rewards businesses that restrict liberty in practice, is fairly similar to the dilemma Peter Thiel mentions in
https://www.cato-unbound.org/2009/04/13/peter-thiel/educatio... , that expanding the franchise brought in voters who do not vote for libertarian ideals. He calls "capitalist democracy" is an oxymoron, and implies that the libertarian must choose one or the other.
In that essay Thiel advocates for capitalism over democracy, and suggests literally escaping to the internet, outer space, or the seas to be free from democracy and find a refuge for capitalism. But I think the better argument for the liberty-minded is to remain within our jurisdictions and choose democracy over capitalism. The rights to vote as you will, and to speak as you will without censorship, and to assemble as you will without restriction, are protected in our Constitution and moreover are widely seen as civic virtues too. The right to run a business as large as you will and acquire whichever other market participants you will is not protected, and we should stop seeing it as a virtue. Who can say, honestly, that the existence of Facebook as it is today is a victory for liberty?