To understand the 80%, you have to understand this: there are over 1000 different cryptos, but people don't buy those cryptos because they like them more than bitcoin - they buy them because they think it can rise faster than the price of bitcoin SO THEY CAN BUY MORE BITCOIN.
Because you can't spend BTC in almost any merchant (there are only a couple of major merchants that accept BTC, and you can't buy most things with it unless you do it P2P), most people who are hoping to gain more BTC are also doing so for the purpose of selling it for fiat so that they can spend it.
If they really believe in a world without central banks like you claim, they would be hoping to gain BTC for the purpose of spending it. But they
can't be doing that.
The reason that they
can't be doing that is because the
number of unique transactions over this year has stayed approximately the same (or increased very slightly) while the price has multiplied by a factor of about 15-20.
Hence, BTC is in a bubble.