I don't know why they don't design coolers which throw the hot air directly out from the ports plate of the cards. Only the blower coolers do it but they lack additional fans and performance is still not satisfactory.
Imagine an M.2 drive sitting next to the card...
Because that's the point of a single fan cooler, if you were to add a second blower type fan it would essentially end up with the fans "fighting" each other and trapping the hot air. The only other option for a stock card is an aio to dump the heat out.