They have slightly different effects
Leap is a 1-action jump that does not require a check.
You take a careful, short jump. You can Leap up to 10 feet horizontally if your Speed is at least 15 feet, or up to 15 feet horizontally if your Speed is at least 30 feet. You land in the space where your Leap ends (meaning you can typically clear a 5-foot gap, or a 10-foot gap if your Speed is 30 feet or more). [...]
Long/High Jump are 2-action activities that require an Athletics check to measure success.
You Stride, then make a horizontal Leap and attempt an Athletics check to increase the length of your jump.[...]
You Stride, then make a vertical Leap and attempt a DC 30 Athletics check to increase the height of your jump.[...]
Notably, Leap is part of the Long and High jump activities, so you do gain the Powerful Leap benefits for those, and Quick Jump reduces them to 1 action. However, there is still a regular Leap action available to you (although as @BenBarden correctly points out, Quick Jump means that you would only use Leap if you were concerned about rolling a critical failure on the Athletics check).