But the thing with Anglicanism being the established religion is that you do, sort of, belong to it by default. And when we were younger a lot of parents got their children christened automatically. And it's a broad church in terms of belief (just look at what some clergy have maintained over the years).
It's quite possible for someone to be able to truthfully state "I am a baptised member in good standing of the Church of England and have been attending my local church every Sunday for the last two years".
I had an ex-boyfriend once who was very active in his local CofE church. He did readings, rang bells, was on the PCC, was elected as a churchwarden in his mid-20s. But he didn't actually believe in the literal truth of Christianity. He just thought that religion (and more specifically Anglicanism) was vitally important to society and that everyone would be better off if they lived their lives as though it were true. Now, he didn't mention that set of beliefs to most people.
He's married now with at least four children. I would be astonished if they aren't going to a CofE school. I don't know whether he's a hypocrite or "actually lying" or setting a bad example to his DCs. I don't know whether it's more noble to pretend you believe for the good of society as a whole than it is for the good of one individual for whose welfare you have a specific responsibility (although I do think it's a whole lot more weird). I don't know how many like him there are out there (surely not many...?) but at the same time I don't know how genuine and fully-thought-out the faith of anyone else is, either.
Interestingly I know one Catholic priest who argues (and will argue in a technical way drawn from canon law, too) that if parents are prepared to have a child baptised as Catholic, take it to church and send it to a Catholic school, then the Church jolly well ought to make sure there's a place for that child, if necessary by expanding provision. What the parents' actual beliefs are doesn't enter into it, because it's about the child who is a baptised Catholic and should receive a Catholic education. But that's off at a tangent.
If circumstances were very slightly different I might be in a position where I had a choice between attending church to get DCs into a local school within five minutes' walk or not attending church and getting them into schools (and, yes, less "good" schools) the far side of the borough two bus rides and an hour's journey away. Circumstances aren't very slightly different, and I don't have to make that choice, but if I did, would I really give a four-year-old a two-hour return bus journey every day with a pious explanation that I thought this was a less crap message? I don't know (well, actually, if I did have to make that choice I'd probably go for option C, home ed).