After much thinking and reflecting, the only benefit I can see  of observing Karvachauth is as follows-

Giving up food for a day by majority of the country's women would go on to save a huge amount of food........and be a substantial help in the foodgrain shortage problem of the country.

The Government should make a couple of Karvachauths in a year mandatory for both wives and husbands...

Apart from that, if men and women honestly search for the answers within themselves, they will not see any merit in this much cherished and much commercialised tradition...