Can't help but agree with you, change is indeed inevitable. This is why G20 is a more powerful forum than G7.
UNSC is indeed part and parcel of WW2 Victors for maintaining their dominance. It gives them a legal protection to maintain their dominance and deny any up comers any role without their consent. But for the up comers to challenge the old established players, they need to set their house in order. The Developing World needs to initiate massive structural reforms within their countries to reduce corruption, raise human development index and create transparency.
Best example would be Germany. Built out of ruins of WW2, through massive reforms and sheer hard work, Germany is by far the Super Power of Europe. Although not a UNSC Member, but it holds far more influence than France or Britain on the strength of its piggy bank. The US or for that matter even Russia, will not accept any additional member in the UNSC who holds a veto power. That is the sad reality of Real Politik. India is taking exactly the right steps, building up a powerful economy and on the side building a powerful military force. If India continues at the same pace for the next two decades, it will be strong enough to bypass UNSC.