Mixed feelings about this.
I don't think the kids education would be disrupted too much, as if the teachers aren't in school, then they aren't going to be teaching - so they will just be a day behind......and frankly there's a lot of time at the end of term to catch up.
Then......who would be a teacher? It's so much about crowd control, with kids who are all too aware of their "rights", but not so aware of their responsibilities, with scumbag parents all too ready to storm into school if their little Chelsea or Harrison is told off for telling the teacher to off.

Having said that, I was at a high school in the 80's. We had strike after strike. I witnessed militant teachers having a right screaming strop at any kids who dared be on campus during their "strike", as it was undermining the revolution presumably.
I witnessed a really good biology teacher who locked himself in his storeroom to mark our mock exams in secret, because he knew if he followed his union and left them, it would damage our forthcoming final exams (I knew this as being a 6th former, I was treated as almost an adult and was trusted).

I knew a militant deputy head who locked a schoolfriend in his office with him, and challenged him to hit him, so that he could have this kid expelled. No witnesses, so we could never prove this happened.
The same militant little .... gave me a bad telling off because I didn't share his views on communism and dared write an essay on communist aggression. My results were marked down because of this. Sigh let's pretend I care shall we.

I saw that school go from a very well respected grammar school, into a sink comprehensive, where parents knew bullying was rife. It's ofsted report showed racial tension and general aggressive behaviour in the school buildings, but the school always denied this.

I knew a top teacher, who was admittedly a real left winger, but a pragmatic one. He believed in discipline, but he gave up trying to keep control because nobody would back him up.

Then we had STOPP - teachers opposed to the cane. Well they got their way didn't they - and they went back to their middle class leafy secondary schools, and rural village primaries - leaving teachers in tough inner city schools despairing.

The words as they sow, they reap come to mind.

Teachers used to use the advertisement to attract graduates "nobody forgets a good teacher". Very true, but also nobody forgets a bad teacher either. Whether it's the lady teacher who just couldn't keep control, leading to her screaming at us whilst pupils climbed out the windows and held a disco in the empty class next door, or the former nun teacher who preferred to preach about being an anarchist instead of teach.

The good thing I can say about the teachers unions, is that after many years, they now seem to have woken up and smelt the coffee - they now do try and fight for teachers, however the damage is done