I know a little about the area. Quite generally speaking, India is quite different from Bangladesh, with different cultures, different languages and different foods that are allowed to be eaten. Bengali regions of India are more aligned with Bangladesh in terms of identity, obviously. Bengalis...
As mentioned, authentic Indian food is far superior. Not all 'Indians' are even owned by those from India. A lot are owned by people from Bangladesh, for example. However, for the purposes of the thread, it has to be the Dhansak.