The problem is unless everyone moves to blake2b then it will never hold value because there can only be 21 million, most will likely mine it and move it to legacy if legacy is the one holding value an...
You're still looking at it through fiat perspective. 1BTC will always be 1BTC if secured by a protocol without 3rd party. That's 1/21M. Core chain has now proven the ability to remove this attribute over time which will make 1BTC less valuable because it will become a smaller part of the full pie. You will then need to compare the size of economy each chain represents. Initially core chain will represent much larger economy but after some time it will be of no use to free people because it will become permissioned through centralisation so for free people such chain will represent a value of zero to their objectives.