Or it’s just a creative, figurative way to express a difficult concept.

Power has corrupted long, long before capitalism. Power and corruption are ancient beings.

Because money robs the intrinsic joys of life.

Lots of research proves it. Here’s just one example https://www.library.hbs.edu/working-knowledge/intrinsic-joy-sparks-ideas-better-than-cash

Also, money is literally power and no one handles power well. It corrupts and the more money the more it ruins people. It really is the root of all that’s bad.