I agree, but I would break it down further. I would say community and regional culture can matter more than religion itself.
For example, Punjab on both the Indian and Pakistani sides has its own strong social and economic culture, despite being in two different countries. Similarly, the Marwari community in India has done very well in business and trade, even though they are part of the same Hindu society as many other communities.
We can also compare South India with North India. Both are predominantly Hindu, but there are clear differences in education, economy, social structure and political culture. So I don't think religion alone can explain these differences. Community, culture, history and social environment also matter a lot.
India and Pakistan both have a mix of cultures and regional differences within their own countries. They share some common challenges, while also having their own unique ones. More or less, the key issues today come down to governance, stronger institutions, better education, sound economic policies, and greater political stability.