It very much depends on the school, but in general, if it weren't for the holidays, like me, I believe you'd be hard pushed to find anyone wanting to do the job at all.
Teaching is an incredibly thankless job without any opportunity to let up - ever. If you so much as make a small mistake or indeed for get to plan just one single lesson, don't have time to mark all the books up to scratch on top of all the tests etc. and your job could be on the line. And it will always be noted by someone, there is no let-up, so imagine having to be perfect and fully-on performing for 7 hours every single weekday and on top of that then work just as many hours around the job just to make sure you stay on top of it.
My current school, I work 3 hours before work (unpaid), 7 hours in school (paid) and another 2 hours in the evenings (unpaid) plus a long commute every single day. Trust me, teaching isn't a job you want to do close to home, or else you run the risk of having to perform outside of school hours, too, as some take great offence at teachers being human beings outside of work. Then typically a few hours in the holidays catching up with marking. I sleep 4 hours a night during the week and am spending the rest of the time working, commuting and maybe see my children for 2 hours a day.
I spend my days being treated like dirt by a lot of the kids.
I am ill every holiday as my body gives up from lack of sleep and sheer tension during term-time.
And I am efficient and good at my job. We've been told that our teaching time will be increased next year, so even less time to do the admin in school. I will be leaving the school at the end of summer like many others. Our school will lose more than half its staff, so that should give you an indication of how worthy the holidays are compared to term-time work.
But I have worked in schools with a better understanding of how to treat teachers like human beings and actually allow time for the job. In some schools, you're not constantly fighting battles with students and senior staff don't constantly try to find fault with your work. The workload is still high, but more managable. They are few and far between and sadly becoming fewer by the day.
So no, the holidays aren't always worth it.