you are correct. Padmanabhan temple apparently has gold worth 22 billion dollars.
https://en.m.wikipedia.org/wiki/Padmanabhaswamy_Temple_treas...
> The valuables have been accumulated in the temple over several thousand years, having been donated to the Deity, and subsequently stored in the Temple, by various Dynasties, such as the Cheras, the Pandyas, the Travancore royal family, the Kolathiris, the Pallavas, the Cholas, and many other Kings of both South India and beyond.[10][11][12][13][14][15][16] Most scholars believe that this was accumulated over thousands of years
Remember that most Roman gold ended up in India. India was the main far East recipient and trading partner of Rome, not China (trade with China was mediated by Indian kingdoms). And that was one empire with which South India traded. It's unfortunate that a lot of narratives about India are driven by the North. The South is way more interesting, in my opinion (I'm biased).
It's not from North India though. North India is not on the land-based trade routes between the Middle East and the Far East due to mountains along Myannmar.
It's from Central Asia and the Middle East, who's views are often followed by Indian Muslims for political scoring against Non-Muslims. A lot of the people in Central Asia and the Middle East absolutely hate Indians and South Indians, so they often tend to write narratives that avoid India. So something like discussing direct contact between the Middle East and the Far East but avoiding India. If you want to read about the genuine geopolitics of ancient India then read some historic texts from the Far East.
The idea of there being a strong conflict between the north and the south is something driven by corrupt left wing separatist and regionalist politicians in South India, but most North Indians don't think like that.
I mean even customs that are 'Indian' in the diaspora are often north indian customs. It's fine, but it'd be like asking a new Yorker to make southern bbq