@TizerorFizz You have it backwards.
The very vast majority of teachers will tell you that they love teaching. I do, have done it for 20 years now and can easily see myself going for another 15 before considering something else.
What grinds people down are behaviour and ridiculous expectations.
Behaviour won't get better until you get teachers to stay in teaching again. At the moment the kids are so used to someone turning up for a day or a few weeks, promising they'll stay, and then letting them down. The kids do not have trust in staff in most schools I have worked in for this reason and behave accordingly; you see that they are completely different with the staff that have been there for 3+ years, regardless of that staff member's ability to teach.
A decently-led school backs teachers over parents, so that's not that much of an issue. The best heads I've known have put the phone down on parents with the words "These are the rules, if you don't like it then maybe we are not the right school for you".
How do you get the best heads and leaders? You take experienced staff who fancy the challenge and train them up, ideally in-house. Kids and staff respond much better to someone who already knows them well than a fresh face. They already know the ins and outs of the school and its vision.
Here is the catch: Because of the ridiculous expectations of the government and, increasingly, parents, any of the above rarely happens.
The pressure to get results which increase year on year regardless of circumstances or the sheer impossibility of this, statistically, and which are tied in directly with the job of the head and some SLT, means that pressure is put on students and staff to get the results by any means necessary. Keeping as many kids in lessons regardless of disruiption, so that even the disruptive kids get, perhaps, a grade 1. An expectation of before- and after-school revision, with some thrown in at lunchtime and therefore little to no prep time for teachers. Persistent scrutinies fo work and pressure on teachers do squeeze more out of the kids. Nothing ever being enough. And because there is no funding or time for training, managers don't know how to manage. Some staff are pressured into management jobs without the passion for it and SLT roles change sometimes yearly to plug gaps - why is a behaviour lead one year suddenly in charge of teaching and learning?
The expecation that schools teach everything. Instead of tutor time being about ensuring students are equipped and nipping any social issues in the bud, tutors now have to teach - usually PSHE, reading (because parents read less and less with children) and extra Maths in the mornings. Schools are expected to show formal lessons to teach skills like resilience and team work when those skills should partially come from home and partially from social times.
But social times are cut short, because schools need the time to squeeze in extra lessons and because financial constraints mean that they need more students than a school can physically hold. So you try to get 1200 students through the canteen in 40min and they barely have time to see their friends before they need to move back into lessons and schools have to actively teach something you cannot teach in an artificial environment. And as for resilience, and over-emphasis on mental health now means that students must never experience failure and increasingly they don't try a second time at all.
The over-emphasis on mental health happened under Blair, too - I remember sports days where pupils were handed a meaningless certificate for participation and where we weren't allowed to celebrate winners lest some others feel left out. We went back to common sense for a bit, but now it's taken off again and this generation's issues are taken even more to the extreme.
Now students are permitted to leave or skip lessons if they experience anxiety in them, now students frequently have toileting issues because they couldn't possibly wait 20min to go (in secondary; I'd have more understanding for a 4-y.o.), now students are in school with weighted blankets, annoying fidget toys of which they have a choice of 10, now staff are called in to mediate between students when they fall out with their friends. There used to be a time when most of the above would have been preposterous to even suggest.
Yes, part of that is a SEND issue, too, which brings us back to ridiculous expectations: that schools educate students who should not be in mainstream, and that both teachers and other students are frequently in situations, which are neither safe, nor are they fair on students who miss out on teacher support when said teacher has to deal with student X 20min in every lesson. Lack of money means no LSA support, so more work and more of a feeling that you fail the rest of the class because of this one student, or sometimes 5.
And then, let's finish on funding. Schools have less and less money, proportionally, to fulfill all of the current expectations on them. They have to not only pay their staff, but also pay to feed kids who are not fed at home, pay to entice kids to be in school (attendance rewards), pay for frequent behaviour issues due to the above (several thousands a year on fixing vandalised toilets and doors are now normal), pay for new equipment (part of which frequently gets stolen, curtesy of tik toc trends), pay for equipment for kids whose parents refuse to let them carry so much as a pen on them, pay for trips and fund them for kids whose parents cannot or will not pay, fund clubs, which are expected as part of the ever-increasing expectation that we use school as full-time childcare, pay for energy on business rates, pay for refurbishments of things like roofs which they can then only get done during certain times, increasing the price etc. etc.
Teachers don't strike because they're left-wing. Teachers don't leave because they're left-wing. Teachers leave because they can have a much easier life on the same pay, if not more, without being ground down and made to feel like a failure daily because of all of the above.