A point made by Engels in Origins of the Family, Private Property and the State is that over the past 10000 years, the economic system has been completely upended several times.

10000 years ago hunter gatherers lived in primitive communism. Then slave empires arose in the fertile crescent. After Rome was sacked, decentralized feudalism became dominant. We still see its vestiges, England and Japan are ruled by royals, officially. Capitalism began taking hold only a few hundred years ago. It may be permanent in our lifetime, but it will surely be replaced in time. I doubt production will be for the purpose of enriching heirs 10000 years from now, or even 1000 years from now (perhaps even sooner).

Marx said capitalism will run its course, until its doing more harm than good. Then it will be replaced by a different system of production.