Kareem won 5 out his 6 rings in the '80s. He won his rings against all-time great teams like the Celtics, Sixers, and Pistons. That's better than Jordan's watered down rings against teams like the Jazz, Suns, Sonics, and Blazers.
The Modern NBA started in 1980 not 1989.
WTF makes 1989 the start of the modern NBA?

The modern era started when Magic and Bird came into the league.
The league started to trend downward in the mid '90s and '99-'05 were literally the worst the league has been in the modern era. Horrible fundamentals, ineffectient shooting, too much one-on-one.
Kobe's peak years came when the NBA was at its worst and he still was never the best player in the league