Regardless of economics, all children do well if private school children enter the state sector.
On the whole it's seen as a good thing if there is a greater number of engaged, middle class families.
Society does better as a whole if children are schooled together rather than siphoning off the privileged ones.
The economic arguments individuals are making don't make sense.
If you are sacrificing things to pay school fees now, you'll free up that money to spend in the economy.
If you're only working to cover the school fees there are plenty of people who would take on that work. You're hardly at the top of your field.
There are plenty of wraparound care options and your kids could well be better off if they see more of you.
I don't make judgements on people's choices but not putting your child in 12 hour childcare when the only reason you're doing it is to pay for the childcare, seems OK to me.
If there are other reasons, such as even more money or personal fulfilment, security etc then carry on. I don't think you'll give up your job that easily.
If you're going to put money into local economy through tutors, after school activities etc then happy days.