Most jumpers period (long jump, triple jump, and high jump) have impressive verticals. The vertical component is super important even in horizontal jumping because it's about trajectory.
As far as MJ, he definitely did not have a 48 inch vertical. I'd be surprised if his vertical was even 40 inches.
The average NBA vertical is actually low 30s, but you combine that with average height of 6'7 and wingspan around 6'8-6'10.
Back to Jordan...
Jordan was NOWHERE near the best jumper...based off vertical. He, like LeBron, are 1-foot jumpers. One foot jumpers are geared toward running and jumping.
Two-foot jumpers generate all of their power straight up and generally have impressive verticals (Nate Robinson, Vince Carter).