Non teaching roles can include
The caretaker who fixes holes in the roof, opens up the site at 6.30am and locks it up again at 8.30pm, having spent the day dealing with leaks, breakages, vomiting, repairs, maintenance, putting chairs out, moving heavy equipment, then comes in every weekend to allow access and supervise private lettings and comes into a dark site at 3.30am alone because the intruder alarms have gone off.
The cleaners who wipe the urine off the floor of the boys' toilets and pick up the used sanitary towels in the girls', clean the floors every night, empty the bins, clean windows & ensure buildings are properly secured.
The catering staff who make sure the kids get one meal a day that doesn't come in a box dripping grease.
Finance - nobody gets paid without them. Nothing gets bought, nobody is employed, no dinner money can be taken, no trips, no books, nothing.
The secretary who is also the First Aider, admissions co-ordinator, dispenser of essential medications and answerer of all queries from Staff, Visitors, callers, emails, phone calls, letters, irate parents that are shouting the odds, reprographics, Fire Officer, Security for the door and providing the tea at evening events - like the expected school plays, concerts
The technician that runs the network, teaches staff and students, manages the AV equipment, the fire and intruder alarms, monitors and ensures internet security
The Pastoral Care who deal with discipline, hold detentions, help the distressed SEN kids, make safeguarding referrals, monitor and follow up safeguarding/welfare/liaise with parents/medical teams, monitor attendance and liaise with the Educational Welfare Officer and Safeguarding Leads, provide admin for Safeguarding Meetings, plus anything else that crops up during the day
The technicians who order, maintain and set up equipment so it's ready for each lesson, plan ways to deliver lessons, provide 1-2-1 tuition, supervise intervention, revision and co-curricular clubs, uses their specialist knowledge beyond what is required of a teacher and stay until long after the rest of the school have gone to get things ready for the morning
Cover Supervisors who teach lessons rather than cost much, much more in private agency supply fees
The TA who takes the disabled child to the toilet, cleans them, gets them changed for PE, stays with them, calms them down if they're having a meltdown and has to get them down the stairs in a hoist if the alarm goes off.
Pretty much all of the above also have requirements to maintain discipline, challenge unacceptable behaviour, spot issues that teachers might not have time to, work with kids on a completely different basis - but all are still important, even if they aren't technically teaching.
With the exception of the IT manager/tech, Finance and Caretaker, the rest are on term time only contracts and get paid significantly less than teachers whilst covering a huge amount of jobs that a teacher could be paid to do - but you'd need to employ far more of them to get those jobs done as well.
Get rid of non teaching roles and you just wouldn't have a school. You'd have a locked building with no resources, no heat, no light, no food and no staff or students.