The scroll fade on that site is comparatively inoffensive (comparatively), because you messed with scrolling itself, which is one of the worst things you can do, taking over and ruining inertia. You’re literally going out of your way to make things worse. The ONLY time scrolljacking of any kind is acceptable is for things like maps where there is no “normal”.
Hijacking native scroll behavior to badly reimplement anything remotely like scrolling is wrong even in a gaming context. But if you're implementing Half Life 2 in a browser, where the user no longer has a normal cursor, then hijacking scrolling to implement the weapon switcher is fine.
Yes, that. Or some weird experimental stuff, like running an emulator for the Playdate https://en.wikipedia.org/wiki/Playdate_(console) or whatever. Games are allowed to be a bit wacky, and no one is forced to play them.
