A few fares
Hey Monty!
Of course the average EZY fare is lower than a full fare airline's average fare - this is because in addition to offering low fares, the full fare airlines also offer higher fares for business and first class which EZY does not have. These much higher fares then affect the average you mentioned. If you insist on talking averages then a fairer one to consider would be the average economy fare (all EZY fares can be considered economy fares can they not?)
Anyway, I found a few fares. These are returns to AMS from LGW. I simply selected dates and chose the cheapest options for the dates, making a brief note of times for comparison.
5/03 – 10/03 LGW - AMS:
EZY £67.10
BA £77.30
BM £59.80
28/02 – 6/03 LGW - AMS
EZY £93.27
BA £102.30
BM £134.20
9/03 – 17/03 LGW - AMS
EZY £58.27
BA £77.30
BM £58.10
Most of the EZY flights were at pretty unpleasant hours and naturally subject to the standard unpleasant terms and conditions of EZY flights. Certainly EZY is not the best option for the 1st and 3rd example. In the 2nd example EZY is only £9 cheaper than BA. I think I would be happy to pay the extra £9 to avoid EZY and fly BA for obvious reasons of convenience and likelihood of inconvenience.
At the moment it would appear that unless EZY is trying to kill competition on a route, they are probably not the best option available for somebody in need of a low fare and reasonable convenience.
edited for mis-use of funny faces...