Some indication of the scale involved.

Ganga basin is the largest river basin in India in terms of catchment area, constituting 26% of the country's land mass (8,61,404 Sq. km)

12 major rivers catchment area is 252.8 million hectare = 77% of total area of India. https://twitter.com/entropied/status/1336934838771675138

These long long rivers would have a ghat every few Kms. These are places where people walk every day to pray while taking a dip in the rivers and then also carry some water back to home, in a bottle.
My father's aunt went for Ganga snana every single day for many decades.

Think of it, We Hindus are extreme expansionists in terms of worship. We won't be satisfied with getting some land for building a temple. We will step out of the house and the temple and leave marks of our devotion and faith on rivers, oceans, hills & forests !

Which implies that a really devoted Hindu govt/ organization/ individual would try to not only defend our existing lands but also make all efforts to capture new land so that we Hindus can keep worshipping without any disturbance.

This is at odds with the values that secular state and modernity is teaching Hindus.
You are told that worship is about private spaces, do it in your home and that it's only between you and your creator.
But our tradition is to make a temple out every rock and tree in sight !

It's no accident that we have sayings such as " सबै भूमि गोपाल की " i.e. all land belongs to Gopala. We Hindus mean that literally!