I agree. I think it's clear why every manager he has played under has played him out wide a fair bit. His attributes suit it. Giroud is a better finisher and better in the air. Sanchez is a better finisher too, so I don't see him playing centrally ahead of either of them.
I know he doesn't enjoy it, but I think he's fine playing a wide midfield role as well, due to his hard work and physical strengths. He's a great ball winner and his link up in midfield is very good too. Even when he plays in a 4-3-3, he still defends well and will track back a hell of a lot.