One of the central concerns of Marxism was placing the means of production in the hands of the workers, and Marxists had serious trouble delivering on this front.
In Capitalism, the means of production turned into yet another product, and in considerable part - without much central planning at all - placed and continues to place said means of production in the hands of everyone who cares to have them.
There are problems with capitalism. But there's some bitter irony in that capitalist systems have managed to accomplish one of Marxism's main goals without the need for any particular policy at all.
Marxism failed for a number of reasons, but to argue that those reasons can be addressed and that Marxism can 'work' if only we apply fixes to it, is to make a critical mistake. Marxism is not just a failure - it is, in large part, obsolete.