Just to drop some science on this thread, the primary muscles that raise the knee are the hip flexors (iliopsoas) which are the relatively small muscles that run across the front of your hips (along with some help from other muscles but it's mostly the iliopsoas). On the flip side the muscles that push your hips forward (i.e. extend them) are primarily the glutes and hamstrings. Your glutes and hamstrings are much bigger than your hip flexors and can generate significantly more force so obviously a knee with good hip thrust will hit a lot harder than just raising your knee.
Or as Ice Cube would "you can do it put your ass into it"
"It's always heaviest before a big PR"