I don't think flying is much more expensive in relative terms these days. There are also more cheaper routes than there used to be with things such as microlighting and NPPL for a start.
I can't really comment about the "quality" of recent PPL's, as other than observing a few of their landings ect I don't come into much contact with them in any quantifiable way. Who does other than, say instructors or ATCO's? What I have seen doesn't fill me with any great horror, at least no more than it ever has done. OK, there's the odd crap landing, the ever widening circuits and maybe bad radio; but then, who's not guilty of these things on occasion? (esp the last one in my case).
Certainly 20 years ago there were very few places you could learn to fly taildraggers, or get proper instruction in microlights ect. Virtually all clubs had turned their backs on the Condors, Austers, Chipmunks or even the wider variety of trikes such as Bolkow Juniors, Robins ect of the 60's and 70's. Everywhere you went it was wall to wall Cessnas and Pipers. At least now ... you have a choice and IMHO training on a taildragger does "help" toward better better flying skill so on that score it could be said the potential is for better now.
On the other hand ...
Reliance on GPS "may" have detracted from good navigational skill because once a PPL has been passed they invariably switch to that form of navigation. Funny thing though? despite GPS there do seem to be lots of infringements these days? ... as there always have been. It doesn't wash that they are all by us older generation of PPL's not being able to keep up with technology and as the numbers haven't reduced, I'd conclude that GPS hasn't made for better navigators! Also PFL's and a few other things aren't practiced with enough realism now ... but that is more the fault of an over eager CAA to prosecute for low flying. Here on the farm I'm near Goodwood and often observe PFL training where an approach is made only down to 500' into a field I KNOW would result in a broken aeroplane! I well remember doing PFL's right down to virtually the flare.
Conclusion.
I don't think there is a huge difference in the "quality" of PPL's emerging now. Potentially PPL's could be far better now than they used to be ... but they're not. Overall I reckon they are pretty equal but have a lot more pressure applied than we used to. There have always been good and bad instructors, good and bad schools and good and bad PPL's ... what's new?
SS