Capitalism has worked beautifully in the US for the majority of our nations existence, until FDR assaulted the Fifth Amendment's "No private property shall be taken without just compensation clause with the "New Deal".
For proof of the above statement see the book "why Coolidge matters".
President Coolidge studied the founding fathers in depth and applied the principals of the founders.
The result was that he was wildly successful as president. He followed the constitution and this was the result. That is why the left hates him so much they attempted to rewrite history in an attempt to hide what works from future generations.
President Reagan studied Calvin Coolidge in depth and even held seminars inside the white house for his staff. He brought in special speakers on the subject of Calvin Coolidge.
History records that both President Coolidge and President Reagan were two of our most successful presidents economiclly and otherwise.
To the extent that capitalism is working less efficiently today, the biggest reason why is Government attempting to defy the Constitutions restraints on Government.
Today Government is attempting to defy the laws of mathematics and to defy human nature by regulations and unconstituional laws such as Obamacare.
PS. Obamacare violates the First, Fouth, Fifth, Sixth, Ninth and Tenth Amendments to the Constitution. Additionally it is attempting to lay a foundation to violate the Second Amendment.