I would argue that markets are a necessary step towards capitalism but it's also crucial to remember that markets can also exist outside of capitalism. The accumulation of money in a society with insufficient defenses will trend towards money being a stand-in for power and influence, but it still requires the permission and legal leeway of the system in order to actually turn it corrupt; politicians have to both be permitted to, and be personally willing to accept the checks to do the corruption in the first place.

The biggest and most salient critique of liberal capitalism as we now exist under is that it requires far too many of the "right people" to be in positions of power; it presumes good faith where it shouldn't, and fails to reckon with bad actors as what they are far too often, the modern American Republican party being an excellent example (but far from the only one).