Yeah but unfortunately India is not a country with win-win mentality.
BD and India will always be neighbors. No reason to be enemy with a neighbour i agree. Otoh India is not a country that have a prosperous BD in its intetest. BD must look to countries like Singapore, South Korea and Taiwan., who managed to build a strong economy despite constrained geopolitical location.
For India to faciliate electric power transit to BD from Nepal and Bhutan is a strategic imperative for it. It actually wants a stable and prosperous NE region that includes W Bengal, NE States, BD, Nepal and Bhutan.
Otherwise it will be a lose-lose for both parties as India's NE does not develop properly and becomes less stable, and both Nepal and Bhutan start to steer away from India and towards China.
This refusal would be seen by BD-Nepal-Bhutan as an unfriendly act and also exasperate the NE States and W Bengal. W Bengal is extremely reliant on a healthy BD economy and has a connection with BD due to shared ethnicity.
There is absolutely nothing to gain for India by not being part of this "energy grid" and everything to lose.
As for those countries you mentioned, they prospered as they were "propped up" by the US for strategic reasons.
BD has no "sugar daddy" like these have and so without India not only will its economic development be hampered but its leverage with both US and China will be limited.
Also, all these countries developed by having strong dictatorships who were solely focused on developing their economies and BD at most will have a semi-efficient democratic model from now on. We know that this is not the best model for 3rd world countries to develop.
We need to take the emotion out, accept BD's geopolitical situation with humility and BD can also become a middle income country just like India will probably do so in the 2030s.