I would expect that if it was better, it would have been done by now.
One thing I can think of is that airplanes and AC-powered room fans have motors that can produce a lot of torque. Computer fans are low-power; I don't think that they can produce the torque needed to efficiently move a 3-blade prop. Of course, that said, there are some - I've used one already, a Beta Nidec 12VDC fan with three blades. It moves a lot of air for its size. And it is probably about 55dB too - it's rather loud, definitely not something I'd want in a computer next to me.
Ah, found
the link for the place where I got the fan a few years ago; and they still have them in stock.
130CFM, 53dB. My 55dB thing above was just a guess too. 800mA rating too - it's got pretty good current draw, so it does have some torque behind it. Notice then that
this 9-blade fan only draws 120mA.