I mean Top players competitions like World Championship or Finals of the Tournaments, other competitions it is possible to use it or not , it is not important, because strong players can win against middle class players as second number, too. To use or not to use openning is choice of player, so it depends on his tacktick and we can not decide is it fair or not. There a lot of stupid opennings moves which just lose , why we will discuss is it fair or not to play it against your opponent ?
Regards Alexander