Bangladeshis were (and continue to be) good tippers, both at home and while vacationing overseas.
Dhaka, Bangladesh (BBN)-Bangladeshi consumers are the second most generous on Asia-Pacific when it comes to tipping, overtaking India, according to a
businessnews-bd.net
I remember I always leave at least a 20% tip minimum whether I visit restaurants or for a haircut.
But IMO and as I have seen, Pakistanis are even better tippers.
There is certain sharam and ghairati involved for both Pakistanis and Bangladeshis, where they cannot "cheap out" on tipping.
And most will fight over paying the bill.
There is also some concern for the less fortunate who serve you in public establishments.
Zakat for the needy is prescribed by religion among Muslims.
en.wikipedia.org