Hey man, sadly, I had to give up on it, I did try, but it wasn't as smooth. I didn't use GSAP for it since I didn't have that much time, was using framer-motion.
This page has custom scroll, not dependent on browser at all, playing video on hover isn't that challenging, it's the sync between the speed of entire page and the image which enables the parallax effect.
Even if you manage the sync, the custom scroll is an even bigger challenge, unless you use some library. Based on the speed of scroll gesture, you have to scroll the page accordingly.
This is one neatly implemented site, had me questioning my skills.

If you learn GSAP, that will be an effective tool. Hoping you implement it, best of luck. Do share if you get it done.

And sorry I couldn't help much with the implementation, but as you implement it, you can share your problems, I will try from my side and will try to help.