Bitcoin addressee are used for making transactions, the addresses can be tracked but it can not be linked to he owners if the owners are making use of bitcoin as a privacy coin without making use of custodial and kyc means for dealing with bitcoin. People like to be private when dealing with bitcoin, so you can not link many bitcoin address to their owner as they are pseudonymous.
But recently, there are many institutions that are buying bitcoin, institutions like grayscale and PayPal.
Many people like privacy and don't want to reveal they have bought bitcoin. The fact that so many addresses that currently have a balance of $1 million or more