> But I don't see why those who 'miss out' on the presale etc. (think banks, governments) would choose to hop on board at a later date - essentially gifting money to early adopters - when they'd be better off simply creating a new coin

This exact same argument has been repeatedly given to explain why Bitcoin would never break above $10, $100, $1000, whatever, or why Ethereum was doomed to stay in the pennies. Clearly the late adopters see more value in entering than they see a problem with gifting money to earlier adopters.

Creating a new coin or forking doesn't solve anything, they would be alone and it wouldn't have any value if nobody wants to trade in.

The value is what people value it at. Just because the supply is bounded doesn't mean its value will increase indefinitely.