Some usernames are genuinely appropriate, hein, @LaughingPig?
Another view:
I used to work in a (publicly-funded) school, not in UK though I taught in English. Contractually, I worked 19.25h per week for 36 weeks per year (so 16 weeks annual holiday). I was not expected to be on school premises when not in class, although I could be - I had my own room, only used for my classes, where I could prepare work when not teaching and catch up on correspondence, drink coffee with colleagues, read quietly, etc.
I was timetabled, as my colleagues, with a minimum of two free afternoons each week. Following the luck of the timetable draw, some days I would start late, occasionally after lunch. I was always home when my children got in, and was able to take them to out-of-school activities regularly.
I did no after-school or lunchtime clubs or supervisions myself; these were taken care of by colleagues employed for that (who did no teaching). Behaviourally-challenged children were likewise dealt with under supervision by non-teaching colleagues - all the children in my classes behaved more-or-less impeccably more-or-less all the time.
No teachers were ever expected to cover for absent colleagues - that was taken care of, again, by a cohort of specially-recruited colleagues.
I was paid more than twice the salary of the job I left to go there, as Head of a large department in a big comprehensive in a northern English town.
For a while I acted as subject coordinator and a staff representative, for each of which position I was entitled to an hour's reduction per week in teaching load (or, as was sometimes convenient for me and my pupils, overtime paid pro rata).
I was contracted for two parents' evenings per school year, and I also met with parents regularly, though not contractually obliged to do so. Generally I had good relations with parents.
And so on and so forth. That was a decent job, with reasonable pay. My pupils did well from their schooling - better, much better on average than their peers from UK (whether in state schools or those dreadful private establishments (or "free" schools, @LaughingPig)). Many still contact me with their news after thirty-plus years, though I am generally remiss at replying.
Teachers in UK, and parents, take note: it really is worth fighting for decent pay and conditions for teachers ... something they certainly don't have currently in UK. "Working from home" would be a (tiny) start ...
You have a long way to go. How much do you value education, British people?