In the past, there weren't huge endorsement deals; the NBA wasn't such a big business, and no one was earning that kind of money. Today's basketball players have very high contracts; basketball has become an industry, and even the worst players in the NBA earn significantly more than players from the 1980s or 1990s.
I think the players who played in the NBA's prime years, the 2000s, should have been earning the most money. There are hundreds of players from that era who couldn't manage their finances effectively; we see the stories of many players websites
Inflation and huge valuation of NBA franchise is the main reason why player salary mark up on insane level
Same with crypto prices back then that normally valued less than 10$ but right now most crypto already valued above 10$ due to the demand for investment purposes.
Basketball becomes popular already worldwide whole NBA is the most popular league right now. It’s normal that all their value will be insanely high.