I do think however it is useful to differentiate between a club and a school. I know that many schools are declared as "clubs" for various legal purposes, but they aren't really.
I'd mark a club as a place which is run by and for the members. I belong to one such - we manage the airfield, have several syndicates running within the club membership, have a couple of part time instructors available to help on people's own aeroplanes, and basically all support each other. We don't have significant formal instruction going on, nor seek it - there are good schools nearby where people can go for anything more complex than a conversion or biennial. It is perfectly possible however for such a club to own aeroplanes and have either paid or unpaid instructors - the important factor is member ownership.
A school is somebody's business, run for profit. It can be well resourced and run, but there are plenty of stories about those which aren't.
An instructor of course is as good as him or herself, and both good or bad may exist in either environment.
There are definitely more clubs in the microlight and gliding world than the "group A" world, but they exist throughout and I don't agree with I-M that they're dead, although I do agree that the mainstream of recreational flying lies away from the increasingly expensive certified GA branch. Microlights and homebuilt light aeroplanes offer flying that's at-least as much fun, increasingly at-least as capable, for a lot less money and are the majority of the future, particularly in the club (as opposed to school) environment.
The future of certified GA is almost certainly in commercial schools and IMC touring and not a lot else. It's just getting too expensive to operate these aeroplanes if you don't have to.
G