Check out this snazzy looking fellow: https://www.smithsonianmag.com/smart-news/scientists-dressed...

Is it repelling or camouflage?

Regardless of perceived ease, they cover this:

"Controlled experiments have used various landing substrates, including striped and solid oil tray traps, sticky plastic, smooth plastic, cloth (Experiment 2 in [22]), horse blankets or sheets, and paint on live animals."

It doesn't differentiate the flies mistaking the cow for a zebra, compared to the stripes themselves doing something else to keep the flies away.

It does when the flies are circling a cow in the UK or Japan.