Would you be more motivated to succeed if you knew everyone had an equal start in life?

Progressivism is best expressed with fascism. Fascist Socialism: “it is Government and not the nominal private owners that exercise all of the substantive powers of ownership: it, not the nominal private owners, decide what is to be produced, in what quantity, by what methods, and to whom it is to be distributed, as well as what prices will be charged and what wages will be paid, and what dividends or other income the nominal private owners will be permitted to receive.”

Yes I would be more motivated as I would not have to worry about others less fortunate than me.