I agree with that but it shouldn't become a problem for the education sector to solve.
Teachers' employment terms and conditions can't just change because sometimes people's plans fall through. Yes, childcare is a happy byproduct of children going to school but I'm not a babysitter and I have zero desire to be one. However much i love teaching.
There isn't enough money in the pot to pay teachers currently - many schools are making teachers redundant because they can't afford them (mine included). There certainly won't be enough money in the pot to pay for a longer school year and shorter holidays.
So, what, are we just expected to do it from the goodness of our hearts?
Rather than expecting schools to be the solution to yet another social problem, other employers/the rest of society could adapt to allow working parents appropriate time off. The government could have managed the economy so that house prices and living costs didn't escalate so ridiculously that both parents had no choice but to work would have been another. There could be more, varied and better holiday provision. Either way, a problem for parents shouldn't automatically be a problem for teachers just because we educate your children.
I would say I don't feed your children, brush their teeth or wash their school uniforms for them but, silly me, other teachers and I have done/do exactly those things.
Long holidays are the only perk/benefit of teaching to employees. Take those away and even more teachers will leave. The holidays aren't enough of a perk to keep many in the profession in the first place.