I feel that the way forward is to decouple flying instructor pay from airborne time. I.e. we get paid from the moment we start briefing until the moment we finish with them. Perhaps at £10 per hour. At least then we will be paid for our input (i.e. engine off teaching) rather than the aeroplane time. This would result in no great cost increase for students over the course of their PPL/IMC - perhaps £200.
When I was learning to fly airplanes, my first instructor was a part-timer whom I knew previously through a gliding club. He frequently remarked that he would save me money by not charging for ground briefings ... but actually he didn't
provide any ground briefings, so there were no savings. Indeed, the overall cost of my 'training' was increased: hopping into an airplane without adequate ground instruction is an inefficient, and thus very expensive, way to learn to fly.