This would be an accessibility thing. I agree. Some people use a big cursor with inverted colors. This should be totally doable in ESO especially in borderless window mode. But that still shouldn't be a requirement.
Does YoloMouse not work in ESO? I know GW2 people love it.
Me, I have enabled the Windows feature that plops a big shrinking white circle around my cursor when I hold CTRL down. It's a fast way to find the thing.