First of all, Kevin Garnett has excellent offensive and defensive abilities. On the 2020 Hall of Fame list, Kobe Bryant and Garnett are both in. Entering the Hall of Fame can be said to be a recognition of strength. Garnett can enter with Kobe, which undoubtedly proves Garnett's strength. Garnett is very strong in the back-playing period and the small ball era, because his position is more versatile, in other words, his offensive and defensive ability is excellent. Obviously Garnett's strength is very strong. If Garnett's offensive and defensive ability is average, Garnett will not enter the Hall of Fame and will not shine in the era of back-playing. So Garnett's offensive and defensive abilities are excellent, so he is actually underestimated.
Secondly, he is one of the pioneers with vague positions. Garnett's official height is 2 1 1CM, but Garnett said in an interview that his height is about 2 16CM, so Garnett's positioning is very vague. Sometimes Garnett is a small forward, but sometimes Garnett becomes a power forward. 2 16CM is tall enough for Garnett to play center, but Garnett is a forward. Obviously, Garnett was one of the pioneers of fuzzy position in that era. If Garnett is only good at playing small forward or power forward, the team will not attach great importance to Garnett. So Garnett is one of the pioneers with vague position, so he is actually underestimated.