Me opening rpgmaker to do some matrix multiplication

I would uh consider that pretty in deep gamedev, even lower than some shader code lmao - so yes you would need to know some math.

Cracking open Godot and using a bunch of premade assets hardly even requires programming, much less mathematical knowledge

Depends on the industry and depth you want to go to, gamedev for example you can do without any, but all lower level custom graphics and physics are pretty calculus heavy.

Website dev can be entirely independent of math