I know my posts in this thread have been along a different line but I say again - if there any
recent reduction in fresh PPL holder competence, it is quite unlikely it can be laid at the door of the instruction.
The whole training business is going about it the wrong way.
Too much emphasis on circuits (lots of sweat, brain just goes dead);
Too much emphasis on the first solo;
Old fashioned navigation skills, inappropriate to present day airspace challenges;
Training planes are mostly wreckage;
Self fly hire planes are mostly wreckage (hard to find non-anorak passengers to come along, so a big chunk of PPL utility value is lost);
Experienced PPLs strongly discouraged from hanging around schools they trained in (because they usurp instructor authority) - this touches on to the "mentoring" project which has been talked about for years, and which most schools will not touch with a bargepole for the reason just given;
Poor marketing fails to attract well funded individuals so only the really keen enter the scene (or the hopeless ones);
Etc.
800 hrs over 10 years is about 5 times UK PPL average!!! That represents a flying budget of the order of £12000/year which is hard to do unless you earn something like £50000 gross, and if you are making that much you are unlikely to have time to do voluntary work; such generosity becomes possible only much higher up the scale
I am not convinced that PPL instructors screwed the business. Admittedly they were around way before my time, but I have flown with a few who were such and got grandfathered to a BCPL or whatever. Some were good, some bad, but all seemed to have done a lot of varied flying. Whereas today's instructor (retired ATPs excepted) have rarely probed the nearest crease in the chart, not because they would not like going somewhere (most would love to) but simply because the syllabus does not require them to.
If there was a golden age of PPL instructors, it happened to coincide with a different era where most normal people
didn't look at a 1950-design plane and cringe. Since then, society has changed and those with enough money to fly tend to do other things.