which could result into low demand of bitcoin
What difference does it make if the demand for bitcoin rises or falls? One BTC will remain one BTC. Of course, we all know the theory that money is a kind of commodity, but bitcoin itself is designed in such a way that when interest rises and falls, the level of complexity simply changes, and the network itself continues to work stably, so it’s not scary if the demand for bitcoin decreases.
What do you mean by one BTC will remain one BTC even if the demand decreases? Are you not aware of the supply and demand rule and how it works? The price of Bitcoin or any commodity or thing increases if that commodity or thing gets a higher demand if it has a limited supply, and the same thing happens in the opposite way if the demand drops.
The interest rising or falling may don't have any effect on the network and it will obviously continue to work stably, but that does affect the market in general, in terms of monetary value. Bitcoin and any other cryptocurrency with a limited supply need higher demand to have a further increase in its price.