This is what I could never understand completely. If most altcoins have fake market caps (some people are saying that you can assign just any market cap to your shitcoin), then why the coins from top 20, such as BTC, ETH, BCH, LTC, XRP, DASH and XMR, constitute over 80% of the total crypto market cap, while all the others, 2,100+ alts, add up to less than 20%?

I'm not trying to say, you are wrong. It's just the whole thing seems pretty strange to me.