I've been both sides of this fence as a primary teacher and as a parent of (a lot) of kids! Must admit as a teacher it was the culture to dislike parent governors/PTA types. As a parent, I never got dragged in. In fact, I didn't do any chit chat at school gates - ever. In the olden days I wore a Walkman (iPod now!) so I didn't engage with other parents. It's just a load of petty crap. Schools should be adequately funded by LEAs/government. Every pound a PTA raises, gets the people who should be paying off the hook.
One of my worst moments, in my time teaching was when the PTA did a stupid money raising fete thing after school and at that place, it was expected all the teachers turned up. Now we weren't on overtime. We were put on stalls - and then had parents whinging, in my case that I made the orange squash too strong... Go swivel. I spent 4 years at uni so I could do this job, and then have to give up hours of my own free time unpaid, essentially so the Head and PTA can wank about raising five bob to build or do yet some other unnecessary crap? (Same school I had to buy pencils for my entire class and chalk to even write on the blackboard, so the PTA raising money for crap were pretty redundant in those circs with that LEA).
So yes. As a parent too, I never got involved. I have friends who have - one who goes into school to listen to kids read, helps out every school production, etc etc - she had an only child and I thought she was naive, really. Now her kid is in secondary school she realises I was right. What a waste of time that was!
I love it when my kids hit secondary school. No more boring class assemblies, no blackmail to help out with this, or do that...
I did volunteer for a whole year to run a crafts group and found it a thankless task. The following year I was mysteriously 'indisposed'.
It is all wank, truly. Once your kids are 11, OP, you will realise you were being reasonable and did the right thing.