there has actually been massive inflation … but … in the prices of financial assets
Up and down cycles of course, but the capitalist economy generally grew strongly circa 1500–2000. There were phases: mercantilism, colonialism, industrialism, and then globalization.
The dynamics were such that opportunities for growth dwindled over time. As growth slowed more and more investment went into financial assets rather than into real productive assets.
Money for financial speculation was available as the central banks tried to buoy economic growth. But the flood of money has mostly just resulted in inflation in the prices of financial assets: