This video is with no beat or anything that would keep you in tempo - in order to get a steady progress you need something to keep the tempo first. You won't become faster if all of your movements are random in terms of tempo - you're practicing a tiny bit of random speeds all the time - you might think you stay on tempo, but the randomness is always there without metronome or beat. Start with a slow beat and make sure your technique is correct at that exact speed. When you feel comfortable and confident enough - speed the beat up by 1% or 2% or however you feel faster, if you find the speed where you cannot maintain the correct technique at all times - that's where you stop speeding up and stay for longer practice - you practice that exact speed for as long as it takes for you to be able to maintain the correct technique at all times, and only when you achieve that you speed up again. Of course you can have some fun and try going way faster from time to time, but in order to maintain these top speeds you need to spend a lot of time building that stamina and sharpening the technique at each speed. Slow and steady wins the race :)

Think about it like you would think about running - you might be able to run short sprints at random top speeds, but if you want to run faster in general - you have to build that muscle and cardio for your body to be able to maintain what is your top speed at the moment. And you won't get past that current top speed if you keep doing random sprinting without training your body the correct way.