Maybe in Australia this would result in better industrial relations and in 20+ year old aircraft being assigned to charter ops only or being flown between maintenance ports only?
New aircraft are worse than older aircraft at the moment as all parts are made just in time for production, when a part fails in service it could be months for a new engine or other major part. So you might have slightly longer time between failures, but when it fails it might be out of service much longer, so its time on line can be much less. The only panacea is having more fleet than services, ie spare aircraft. The only thing a new aircraft does for the operator is save on fuel and maintenance due to efficiencies and warranties. Your redundancy program, quality of maintenance and choice of type will decide your dispatch reliability.
I like how Ryanair seem to think that technical difficulties and striking staff are 'out of their control'. Pay staff more, keep more spares, don't charge 5 pound for a ticket....