Looking at the last available financial results for Scoot, their breakeven load factor is almost 90%! For comparison, Ryanair's is 84%. Meanwhile, even AirAsia is still not profitable with a 89% load factor.

But then, I've always scored very cheap fares with UO - significantly cheaper than the main line. Not sure how the others are playing the LCC game but they've got plenty of super specials happening throughout the year. You just need to know how to play that and make your trip truly LCC - no add-ons and be super flexible with timing.