Generally people who are 2 foot jumpers are stronger, more explosive and utilize their strengths more compared to 1 foot jumpers. 1 foot jumpers are naturally more "efficient", they are more reactive, and their limbs are usually longer and they utilize their body structures and reactive ability rather than strength and power to achieve their jump heights.
Usually 2 feet jumpers are better at the acceleration phase of a dash (0-30m) and 1 foot jumpers are better at maintaining and reaching top speed.
What you will see is that a lot 1 foot jumpers covert to 2 foot jumpers as they get older and become stronger/heaiver etc. It is much more difficult to improve your 1 foot jumps, but you can increase your 2 foot jump heights/standing vertical leaps significantly with strength gains.
The reason for this is probably because it is more difficult to improve reactive ability coordination and cns characteristics and impossible to improve upon body structure, both play a large role in 1 foot jumps.
I've seen a lot of people who naturally jump with 1 foot reaching their jump peak by the time their puberty ended and they would jump the same height with 1 foot after adding as much as 200 pounds to their squat, but their 2 foot jumps/vertical jumps increased significantly.