The India that gained independence is India + Pakistan + Bangladesh + some rounding errors.
The independence of India was immediately followed by a sectarian war between muslims and hindus in India (started by muslims) which by a number of measures was bigger than WW2. Gandhi immediately turned into the commander-in-chief in this war, a war where millions died, and Gandhi came out on top.
After which Pakistan, now independent, started another war with yet again millions of dead, against "East-Pakistan", to prevent their independence, now known as Bangladesh. This war was a continuation of the partition wars in many ways.
Pakistan is not far from starting another of these wars, by the way, against "Balochistan", the south west of Pakistan.
Same with the war in Ukraine, even if Russia managed to conquer all of it, would the world recognize that Ukraine belongs to Russia? I don't think so.