Islam's propagation through Bengal, relative to the rest of the subcontinent, was much more peaceful. it was through trade and commerce with the Arab world at the time.
If you think about it, the fact that Bangladesh today is this tiny enclave with this huge Muslim population, in a very non-Muslim area, is quite remarkable. Not many countries around the world can have such a high % of practicing Muslims, who are completely surrounded by non-Muslim, countries. Especially when Islam wasn't really forced there, as it was in other parts of the subcontinent. It shows the power of Islam as a culture if propagated in a way taught in the Quran (IE, not by force). The other example I can think of is Indonesia. And for similar reasons, it proliferated through trade.
Whereas in a lot of other parts of the subcontinent, it wasn't so peaceful. It was through military conquests. So large swathes of landlocked connecting lands were easy prey to conquering militaries, resulting in a lot of forced conversions. Modern-day Pakistan is an example of that.
This is controversial. But I believe these historical differences manifest in subtle differences in mindsets. But it's not my, or anyone else job to say where the best manifestation of Islam lies. But if we were to point compare the pseudo, even anti-Islamic practices going on in Pakistan and Bangladesh, we'll be here all day.
But the idea that Pakistani's have the sole authority to speak on behalf of all Muslims in the sub-continent (or even the entire continent), is kind of laughable if it wasn't so historically tragic. This is why so many Bengali's to this day loath Pakistani's, with a passion. Because you put yourself as the sole authority of all things Muslim in the subcontinent, based on your shallow lessons from history, which has little to no relevance elsewhere. For you, India is your eternal enemy. That's your business. But please, leave religion out of this. We have problems with India too. But we'll deal with them our way. Not the Punjabi way.