It's a joke.
I had a job offer recently where I can pretty much name my price and working conditions. All because, in that school, the department I'd be working for will be running on 50% qualified staff from September. The HOD there is tearing what little of his hair he has left out. It's a shortage, core subject.
In my current school, Y7 have at least one lesson supervised by a cover teacher a day; sometimes they can have as many as 3 out of 5. That's not including the fact that their form tutor is whoever happens to be available that day. Then they come to my lesson and are completely unsettled, so more learning time gets lost.
It's slightly better for Y10 and 11 as they are being prioritised, but they still have had a lot of cover this year. No specialists at all for science lessons, it's completely normal for a Biology teacher to teach triple Physics and beyond and lots of PE staff have been roped in to teach Biology and Chemistry instead.
We have had 3 heads of departments leaving and cannot find anyone to replace them. TLRs aren't worth the money, so no one in house will do the job and too many teachers are ECTs, so not qualified to do the job anyway.
Results are slipping, so we're in Ofsted panic mode. The average life span of a head teacher in my school is 18 months, so there is no consistency.
We're not allowed to hand out books anymore, so kids now work on paper for what is still the best part of a half term. No more money for glue sticks, so nothing looks good anymore. GCSE kids will not receive new books next year and will continue to write into their old ones until full to save just a few extra pounds. A broken lift, a handful of blocked pipes and a few broken fume cupboards means we only have 2 fully functioning labs for 10 science teachers, so most lessons are theory only.
There is no money to replace broken calculators, so unless kids happen to have a phone or bring their own (they won't) it's tough and then we get complaints that the kids can't access their lessons.
I get a minimum of 2 cover lessons a week right now, as do my colleagues. We're meant to be improving resources for next year, but all of our gained time is being used to staff things we can't afford to get people in for anymore, e.g. invigilators for mock exams, TAs to aid with reading and scribing.
Schools are on their knees.