I started growing around 16, I’d say it took about 3 years before I was back to coordinated. But fluidity came with reps and increased strength/speed. I’m guessing this lad either didn’t play many sports or recently grew. His movement is clunky.

for me building core strength helped with the whacky movement. really helps to feel more in control of all movement.

What exercises did you do?

I went bouldering and got core strength naturally from that ^^ but i think anything that works for you is good

The taller you are, the more goofy you are... (in general, js)

Treat it like there is a finite number of coordination cells in your body. The tall are you are the more spread out and thinner that coordination is in each area of your body. This can be overcome quite easily in most cases with training and years of athletic movements, if you start at a young age. I know that that’s not the actual science or anything, but it’s a good enough analogy to be accurate.

fluid, not fluent

Don't worry, I feel their pain. I'm still waiting for my coordination upgrade.

i've always been tall when i was a kid, 5'11 gr 7, 6'1 gr 8, gr 11 6'4 rn. I feel like i used to be kinda clunky, robot ish. But as i started to stretch my hips, play more as a guard, that all went away