One of the problems with Necker, you had the reverse situation; the conservatives didn't like the man because he was a commoner, a foreigner and a protestant. His being otherwise an overconfident and at times difficult to work with man above this led to the additional problem that he was very very fragile as minister of finances (he didn't even get the title) and moreso than the others of the ministers in Louis XVI's cabinet he was extremely dependent on royal favor to stick around.
Also another problem is that a lot of his cuts, while practical in cleaning the finances of the court department were doing a lot to skirt the fact that it was nowhere near enough. Louis XV had had the same issue about 30 years earlier. The reforms that were needed included things like a proper cadastre of the provinces, but when it was tried in Normandy the provincial authorities in charge of it did everything in their power to stop it. French estates were very very well known at the time for cooking their books when it came to paying crown taxes. The other needed reform, taxing the church was not politically possible even for Louis XVI, who was significantly less reliant on the church than his predecessors.