From what I've been reading, it's 'time'. Of course, it's better to have all those which is why it takes 2 years extra. Many people make it into the airlines without a degree and choose to get one after they've been accepted. I think it all depends on your luck and each individual. Some may be very good at flying while others are very academic and some may be good at both.
However, I'm not saying getting a degree is bad. I have not yet experienced up to that far yet. I still have a lot to explore!
Cheers