@FrancesCrawford, State Funded schools use, for want of a better word, templates detailing the skills required of Support Staff in Education (and other departments) for recruitment, assessment, appraisal and setting the appropriate levels on the pay scales.
If somebody fulfils the required competency level at appraisal, they are doing what is required of the role (and there is no leeway for recognising people being more capable/having higher level skills - it's a Yes/No or Achieved/Not achieved situation, so there is no way to get paid more in that job if you are capable of more than the standards).
School Reception/Admin is generally classed as a Grade 2 position - those skills are of the kind I have already listed - being able to write a To Do List and write down a telephone message are genuine achievement levels a Grade 2 postholder is required to have. There is no requirement for perfect writing, no requirement for Numeracy, no requirement for using Excel, Word or anything more than possibly being able to operate a photocopier with training.
This doesn't mean that all Reception staff have only those basic skills, but it's all that's required to meet the specification - somebody just meeting it is more likely to accept the miserable pay because they aren't in the position to pick and choose in the way somebody with better qualifications/skills might, as they could get a job that paid better and required a higher level of skills.
A rough analogy would be;
I'm running a clothes shop. I want people to think it's a desirable brand when passing (and probably get some online presence), so I've decided I want somebody young and pretty to stand outside the entrance.
I don't need them to do anything but look young and pretty.
If I expected them to do the accounts as well, I'd have to look for a qualified accountant who was pretty and didn't see the main part of the job as demeaning - and they'd probably expect to be paid more. But I don't. I just want a human mannequin.
As such, if I recruit the prettiest applicant that accepts the rate I'm offering, I'm not bothered about their examination results.
It doesn't matter to me whether they turned up for their GCSE exams or gave up after failing to get their Bronze Swimming Certificate. And if, because I'm a pisstaking shitbag keen to keep staffing costs down, I get them to stick a few boxes of shoes on the shelves when it's raining to save paying somebody else, it's not a disaster if they mix up the reds and the greens. I'm not paying them to be smart/well educated/not colourblind, I'm paying them to be pretty It might annoy a few punters, it irritates me a bit, but I'm paying peanuts and don't want to be doing the shoes myself.