Franz. Have you lots of evidence for all the statements in your first paragraph?

Which of those statements would you dispute? Franz S is making the reasonable assumption that "entrepreneur" is equivalent to "self-employed".

Professional folk singers are entrepreneurs. Would you regard most of them as wealthy or running large businesses?

For every Bill Gates or Donald Trump there are thousands of plumbers, window cleaners, shopkeepers, market gardeners etc running their own business without being "wealthy".