I am more bullish on India than most people here. Still for the foreseeable future it won't be China. If demographics is everything, why Egypt didn't pass Germany?
Nah. India will never become like China. India is just not China. When China was rising fast, nobody said that China will become a much larger Japan. India is a South Asian nation, while China is an East Asian nation. Comparing India and China is like comparing Nigeria and Brazil. Two developing countries of roughly similar populations, but with very different geographical, cultural, historical, and economic circumstances.
You're right. Demographics is not everything. Indonesia has the 4th largest population in the world, but is only no.16 in economy. India is no.2 in population, but is no.5 in economy. Even China, before it took off, was already more populous than Japan and the US for a long time. Nobody before the 2000s even entertained the idea that China's economy is gonna surpass Japan's, let alone compete with the US.
So yes, India is gonna overtake the population of China. But that doesn't mean that India will become a bigger economy than China. That doesn't mean that India will become a superpower. India may have nukes and a space program. But those are still not the quality of a superpower. Israel and North Korea have better nukes and rockets than India. Nobody considers them superpowers.
Knowing how Indian culture works, I understand that India is a nation of hype. It'll get somewhere for sure, but it won't achieve anything near the hype. Indian culture is missing a key quality to become a great nation: integrity. Without integrity, there is not enough trust. When there is not enough trust, shit don't get done. When shit don't get done, then nothing great can happen. India is the only nation in history to hype itself up as a superpower before doing anything. The other true superpowers in history only realized they were superpowers when they did great things.