I think that's one of the most difficult aspects of the later books, tbh - it enormously undermines Miss Annersley that she can't seem to cope with really quite basic problems without sending them to Joey. I appreciate that it's a plot device to keep Jo present (and centre stage) but it has a great cost. It's also a big part of why Bill and Madge are so sidelined, I think - fewer other possible voices of wisdom and experience to detract from Jo's role of Solving Problem Girls. I can see it on occasion, phrased as "I think this girl is having X problem and it would be far more helpful for her to hear sympathy/empathy/advice from a non-official adult", kind of similar to when the prefects deal with a problem themselves without involving the staff because it changes the nature of the thing, but it's just this automatic 'girl is unhappy, naughty, aloof, jealous, un-Chaletian? To Freudesheim she goes!' nonsense.
Maybe that's not even what EBD wanted herself, by that point - maybe she/publishers couldn't see any alternative but to keep Jo as the thread running through the series, the 'spirit of the school' holding it all together. I don't always feel that she enjoyed writing the later books, which is entirely possible I imagine - after forty years, she could quite easily be sick of them! And afaik she always needed the income.
Agree that Madge is a much more plausible character. I think it's interesting that EBD seems to recognise she's basically run her course by the middle of the series, but doesn't seem to think the same of either Jo or Miss A, who continue being predictably 'nothing but a Chalet girl, spirit of the school' and 'justice tempered with mercy, excellent eyesight' for book after book after book. It's this that makes it formulaic, I think - she experiments with peripheral details like motorboats and astronauts, but the number of central tenets which are unchangeable just seems to increase and increase and increase.
I think Grizel is similarly realistic - spends many years in the job she didn't really want to do, sees the man she thought would marry her marry her friend and business partner etc. I do think characters like Grizel and Madge provide ballast for the more idealised Jo and Hilda - some people in life do compromise more than others, and what represents an unbearable compromise for one is the best of both worlds for another. I would absolutely hate Jo's existence - she continually harks back to things which happened when she was 16, because those were the best days of her life, and never seems to have anything to say for herself in the Swiss books apart from these reminiscences, plus news (usually husband or baby related) of other Old Girls. Going back to "we don't get paid much, but we do see much" - I'm always struck by how very, very little Jo sees, and I'd hate that. But she definitely gives no indication of being stifled or unhappy with her lot.