You are talking of children only of primary age. Trust me, a school day is short. You will not get bored and you will most definitely fill your days with household chores and the perpetual school admin that seems to go on. Plus, this is when you can have your hair, eye, doctor, dentist appointments, shop for clothes and other things in peace and dye your hair, if you wish.
I work but it's shifts and fits in around the school. I never seem to have enough time for the things I need to do. I simply could not manage a full time role, which I would need if my children were to go private. I would totally be a SAHM if money allowed it and certainly would not work to pay school fees if I didn't otherwise have to.
The parents I do know who've opted for private education are working themselves into the ground and stressed out to the point of making themselves ill. Some children are doing well but I reckon others are doing the same as they would in the state sector. The ones I know who have children who are not so bright are still that way in their private schools.
And, in principle, I don't agree with it but I know that's not the point of your post and I do understand why people go for the private sector - the facilities are better because they have more money and the class sizes are smaller.
Someone further up said your child would have a 'better standard of friends' and this sums up the reasons for my disagreement - especially when they went on to talk about knowing doctors, solicitors etc. Unfortunately, mine don't really meet that 'better' standard as my DH and I do not have high flying jobs and we are OK with that. And I would not want my children to feel they have failed if they did not go to university or have a career (or felt it weren't for them) though I would totally support and encourage that if it were what they wanted or they showed signs of being able to achieve that. I just don't like the elitism associated with it and if a relative of mine were banging on about it, I'd be on my soap box like a shot. .