The Maginot line did “work”, to the degree that it reduced the number of men required to hold that part of the front line in 1940. France had a serious problem with manpower in 1940.
The real problem with the Maginot line is that it was not extended far enough north. The principal stretch of heavy fortifications ended just south of Sedan, which was where, not coincidentally, that the Germans broke through.
Had there been a series of “ouvrages” at Sedan, that would have, for one thing, reduced the effect of the Luftwaffe on the French artillery, and the guns of the ouvrages would have retained coverage of the Meuse crossing points, making it more difficult and costly to establish pontoon bridges. More and better bunkers would also have complicated the job of the German engineers in clearing the direct fire defenses, and the ouvrages and deeper bunker systems would also have been bones in the throat of the forces attempting to exploit beyond the Meuse bridgeheads. This all would have bought time for the French reserves to come up.
“Fixed fortifications are monuments to the stupidity of man.”