23w is still available in the usual stores/supermarkets. I think the problem is that that is the largest size that can be sold without power factor correction which puts the cost up to more specialist levels.
IME there were a number of early failures of CFLs, typical bathtub curve, but since then they have proved reliable. I've been retiring them because they do get gradually dimmer without dying but have now gone over to LEDs for the open fittings. Instant on and much better colour rendering. I find the CFLs too red at the compulsory 2700K.
Like many, I've still got a large box of the freebie linear ones which never seemed to fit any light fittings unlike the later more compact spiral types.
ChrisK