The thing is, most people who work in big tech eventually end up on such platforms, maybe searching for more knowledge info news etc. (personal view) and thus you end up seeing a lot if these inflated salaries.
I graduated this year from a t3 college, secured a faang offer, and currently make more than what you mentioned. But this isn't the scene with all if my friends. Most of them are working at mncs making 6-8lpa, and only a very few of my buddies (4-5) made it to big tech/startups/intll offers making similiar to what you mentioned.
On the other hand, my friends from t1 colleges, got placed at flipkart, slice, amex, etc. You get the point, and all are making crazy monies.
Like i said in my first point, mostly people making fat paychecks end up lurking and seeking validation on such platforms. Others, maybe not so much, or maybe aren't so vocal about their pay, thus less visibility.