I hear this a lot but I don’t put any confidence behind it. This argument suggests that one day we’ll be able to brute force into lost wallets when we can break the encryption. Who knows how far in the future that will be.

But if I recall correctly, Bitcoin’s protocol is consensus driven. If there is an imminent threat of quantum computing, the developers could just improve the code base to resist it. Or fork the protocol to one that is resistant (Bitcoin 2). Then it’s up to 51% of the Bitcoin node operators to adopt the protocol. As soon as 51% of them upgrades, you immediately stop the threat.

I think the only reason Bitcoin is around is for two reasons: speculation, or the persons that actually believe it’s decentralised hard money free from control. I’d like to believe that there are a ton of people out there that run the BTC nodes to keep it decentralised. If there is an update that will resist quantum computing, I’m sure they’ll be eager to immediately upgrade their nodes and secure the network and those wallets. At least that’s how I believe it works, it’s been years since I first began researching it.

As an aside, Bitcoin isn’t for me because I hate the environment impact. I hope one day it will become green, because it’s never going to go away. But I don’t blame the people that believe in it. In a world where the rich own everything and control the rules, these people are trying to opt out I guess - use a form of money that can’t be easily controlled or censored. Granted it’s all based on speculation, and whenever we run out of Bitcoin is probably when the system will become useless. Spending is discouraged when you run out of coins, so I don’t know how the Bitcoiners defend that argument. So definitely not for me.

Edit, on mobile so fixed some typos and clarified the 51% attack.