For some reason the web build is different from windows build. It might be the low framerate on the web build that makes looking around way too slow. Looking around on the windows build is way faster. I must have made a mistake in the code when making the effect...
Viewing post in Isolating Waters jam comments
I looked into the code in more detail and I realized I didn't make turning framerate-independant. Well.. I tried, but I didn't do it properly. I used a mix of Time.deltaTime and Time.fixedDeltaTime in Update(), when I should have only used deltaTime. That's why the turning was incredibly slow on anything less than 60fps. Even 60fps was slow since I tweaked the settings when using 144fps...
It's a pretty dumb mistake, but I already fixed it and will update the game when the voting period ends.