One of the problems is that either no-one does anything - and then we all have a shit school. Or a few people try to make it better for everyone. It doesn't have to be like that.
At my kids' primary the school was failing. The parents were determined to give the best for ALL the kids. We had a new Headteacher who had been brought in to turn the school around. Together we did just that!!
There were craft clubs and athletic clubs and dance clubs and a chess club. The sports team was well supported. There were loads of trips, there were food fairs and talks and Christmas/Easter/Summer events. We repainted the buildings and did the garden/play area at weekends. It was fabulous! We raised money and everyone gave something, time, money, advice, resources.
If you are work get your employer to donate or sponsor. If you have a Nanny or an au-pair involve her. If you have money, give generously. If you are not free during the day offer to do admin in the evening. (It just has to be once a term!).
Whatever your circumstances there is always something you can do. The attitude that the PTA is a group of non-working up-themselves middle class mothers is simply not true!! (Unless you want it to be)
The school became one of the best. It was happy and the kids did so well. Then as it went up the league tables it attracted people who just wanted to get in because it was good. No local connection. No sense of the school being a community school - it was something they had "bought" if you like, ( although it was State)
The attitude was "Why should we?" and it became the same few. And the kids got less. The trips can't go ahead if there are not enough helpers. The clubs can't run unless the teacher gets at least two adults to be present - etc etc.
It's a shame really - but it is the way of the world. You get people who give and people who take.
An unpopular view maybe - sorry.