As other posters have noted, China's biggest advantage was concentrating on universal literacy, primary education, infrastructure (everything from transportation networks to amenities like sewage and indoor plumbing). Interestingly, much of the groundwork for this was laid down in the Maoist period itself. Credit where due, I have criticized Marxist-Leninist regimes for a lot of things (I think very deservedly), but one thing they are generally good at is raising HDI, literacy and in building basic infrastructure. This is extremely important. So when Deng started his reforms in the late 70s, all the foreign investors found that they had a literate workforce, an adequate power supply, and reliable transportation networks to get their goods to market.
In contrast, India never built the sort of infrastructure foreign investors love. A recent CBC story detailed the reasons some Canadian investors (including even Indian origin businesses) were more bullish on China than India. No reliable electricity generation (there are frequent blackouts and "load shedding" even in industrial cities like Chennai and Bengaluru). Less literacy than China. India, in contrast to China, concentrated on building world class IITs, IIMs and management schools. This has helped Indians become CEOs of Western corporations like Google, Adobe, Coca Cola and Microsoft and become Doctorsheading major Western hospitals (so much so that it'sbecome a meme), but it is clear China's approach was superior in creating a generally well educated workforce. And then there are the problems like open sewage (a huge turnoff for foreign investors, not to mention a health risk), poor roads, clogged ports, differing laws and regulations from State to State, etc.
Well, "doing nothing" is certainly a big stretch; India has seen major improvements in poverty reduction, economic growth, et cetera.
But India's not doing exceptionally well, either. It's really about average. There are other large multi-ethnic post-colonial states who've maintained stability and relative (if flawed) democracy; see Indonesia and the Philippines[1], who are also roughly in the same economic ballpark as India. Nothing awful, but nothing exceptional either.
That said, compared to China's phenomenal post-Dengist economic growth, India really is pretty mediocre. Despite arguably having a better start than China, which underwent the Japanese invasion, Mao, a horrific civil war, more Mao, horrible famines[2], etc, and being democratic to boot, India's like several times poorer.
[1] Well, besides Suharto and Marcos. But then it's not like India's hasn't had it's own "
dictator"-lite moment either.
[2] Well, India's didn't exactly get scot-free here either, but the Bengal famine and Partition aren't really in the same league, devastation-wise, to Mao and Japan.
I think this is a fairly nuanced, balanced answer. I mostly concur.
The posters who say that India has been a "failure" are exaggerating. As someone who has traveled to India frequently, from my first trip as an 8 year old in 1980, and returning every few years until my last trip in 2017, I can state that objectively speaking India has improved materially each time. A new road here, a new college there, more and more people educated than ever before, more and more people online, etc. And the statistics bear that out, generally improving HDI, improving literacy, falling birth rate, slowly but surely improving infrastructure (both amenities and transportation), and with some inevitable reversals, a rise in both nominal and PPP GDP per year. This is especially true in the southern states (where my family originated).
But no, it is definitely not China, it isn't even in the same league. I agree with you that it is better to compare India with countries like Philippines or Indonesia. Yes those countries are richer for now, but I can see at current growth rates, India plausibly reaching the economic strength and standard of living of those nations in the next few decades.
China? No. Barring some kind of near-ASB level destruction/Civil War in China, it isn't happening.
As stated, China laid the groundwork for their boom decades ago, long before Deng. India took a different path. Not exactly a failure, as some falsely assert, but far from China. Very very far.