>BTW how you reach consensus on a chain is different from how the accounts in the chain are secured. Just because all BTC nodes are burning up electricity all the time does not mean that your accounts are more/less secure.

I think you're drawing an unnecessary line here. Attacking consensus is attacking the value stored in the accounts. Attacking consensus by using your own miners to pull off a double-spend can directly take value back out of accounts. Attacking consensus by doing a perpetual 51% attack can block people from using their accounts, decreasing the real monetary value of them.

Drawing the lines so that the "security" of a cryptocurrency only refers to the security of the public-key cryptography involved in it is useless. It ignores practically all of the important design considerations and attack vectors in the system. Public-key cryptography is just one component of a cryptocurrency.

I am not a non technical user, and I know how this works.

Btw, you are not correct. The entire history of the chain and balances is protected by the hashrate. With sufficient energy you can rewrite history. This is because every block secures the blocks before it. Yeah checkpoints can be used to force a known sync point, but this vastly undermines the decentralization of the chain.