>Do you know how many different empires, rulers, internal wars and government systems China and India have gone through in 2000 years, and how many "races" and "cultures" they have?

Yes. Still more homogeneous and stable than most other empires...

Oh you mean like that time when the Mongol conquered and ruled china for like, 100+ years, ushering in the largest case of minority rule the world had ever seen to that point.

https://en.m.wikipedia.org/wiki/Yuan_dynasty

I mean like that time when this was just an episode in millennia of history...

I also mean like that time when the eventual demise of most empires and huge nations was my point, which China and India managed to avoid, and not China and India themselves (which are totally orthogonal to the point I was making, and in fact an exception to the rule I posited)

India is called a sub-continent for a reason. Its extremely diverse in race, languages, culture, climate, religions,genes etc. Definitely more diverse than Australia and probably more diverse than Europe.

>Its extremely diverse in race, languages, culture, climate, religions,genes etc.

I believe you meant ethnicity, not race. Also as for the diversity, the two major ethnicities in India are Indio-Aryan and Dravidian, at 73% and 24% respectively, leaving the rest of the 'massive diversity' spread across 3% of the population. Same holds true for language. So I'd argue that the actual ethnic/language diversity in India is rather small in practice.

I don't think you know much about China nor India.

I recommend reading about the Three Kingdoms as a starting point.

As for India, look up Pakistan.

The idea that I wouldn't already know of those things, or that they somehow invalidate what I wrote, I find fascinating...

Meanwhile, I've mentioned Pakistan already in another answer many hours ago...