just watched Panipat. why is it called great betrayal?

If you watch Panipat ( terrible movie but look at the big picture) , many rulers both Hindu and non-Hindi refused to help Marathas because they found them even more evil than the Mughals with their raids and demands for unfair taxes. which was double of what Mughals used to recieve.

and the movie projects it as 'the great betrayal' lol what betrayal, they were arseholes.

Everyone is a hero in their own story or at least they want to be.

So, it is 'great betrayal' for them , the one who agree that it is indeed betrayal.