yup, Pakistan isn't Indian cup of tea anymore. India has more problems with China and would love to sort them out. Pakistan isn't as beneficial to India as China is.
It'll take a few decades for rest of the people to understand India v Pakistan is history.
To your last sentence, India will very like much for Pakistan to stick around but fail as well (not collapse). This'd make future sikhs to think twice before 2 nation theory, or other ethnic states.
Also if Pakistan fear losing, they'd resort to nukes. Seeing this, world will push for peace and supply Pakistan army with better gadgets. Such was the case with Israel. They threatened to use nukes if they were to lose the nation.
So yes, India doesn't have any fantasy and waste a lot of their resources on Pakistan and would very much like to focus on China.
Edit: I just want to add, this thread is full of lol. So many people saying "if India does this, they won't have anywhere to run" or "they do this, we do that." Despite the COAS saying internal threat is greatest threat to Pakistan, we still think India is the actual threat. How many Pakistanis army and civilians died at hands of terrorists and how many at hands on India after 1948? @
Contrarian you know?
Once Pakistan is weak, India "will" take Kashmir. That's the land they really want anyway.
Anyway, there isn't going to be any war in next many decades. If India has the itch, they can just stop trade with Pakistan and that'd do somewhat of a damage.