I agree with you that these changes will be irreversible, not least because Labour started the process, LAs will have lost skills and expertise etc etc. But also faith in the state as a provider of services has been so dented (perhaps with reason - I just don't know).
So I think the sort of hard info that prh, and other posters who clearly know their stuff and do not conflate facts with opinion, provides is invaluable - I really want to understand the detail of the process. Then I can challenge my gut instinct that not only do I not want schools to make profits, I would like them to be publicly controlled - and see if the facts support it. If they do, then I will be better placed to oppose them.
Some LAs performed well in their scrutiny role and others did not - but often the information they gathered was not available to the public, in the past. The FOI system has not replaced LAs providing information - it is additional and applies to all public bodies, and is a legal right. Of course you have to know or be able to work out how to exercise it - I never said you didn't. But the bar is not set artificially high.
There is a new field - data journalism - that mines the huge amount of detailed data now available, including that being dumped by government into the public domain. Analysis and journalism doesn't seem to have quite caught up with it, but it will happen (I hope - there are certainly a lot of courses!). In the meantime, if you type secondary schools league tables into google, you get a lot of detailed info about attainment, subdivided by children's previous achievement levels, subjects studied and so on. Much more information than a few years ago. It isn't perfect, I am sure still causes anomalies in the way these things always do, and no, it is very hard to make complex, technical, statistical information accessible to everyone, but it is there and everyone can see it if they wish to. And crucially, a national standardised system means the information is presented in a comparable form.
So, on balance, I just don't know. If all LAs had performed to a decent standard I would agree with you - but I live in one with a track record of decades of educational failure (not any more, happily - is that because it has less control over schools or because of the extra cash Labour put in? gawd knows)