Let me be more specific and make it easier to understand.
If you have a cold wallet, and you use it to generate seed phrase, keys and addresses and no one knows your seed phrase nor private. In the post quantum world, if you make transaction, the public key of the address you used to make the transaction will be known on blockchain which quantum computer only needs to brute force your bitcoin address private key. That is the reason it is advised that people should not reuse bitcoin address this time. Cold wallets are not resistant against quantum computers. What is resistant against it for now is not to reuse your bitcoin address.
You seem to forget that we currently do not have quantum computers powerful enough to brute force the public keys of a cold wallet to get the private keys. The current quantum computers we have now lacks the required qubit count, coherence time and the power to perform such a complex calculation.
It'll only take quantum computers with the IBM's 1,121 superconducting qubit processor to perform such a task as this is the only way to unlock the full power of quantum computing, and mate I don't think we have such computing power right now.It’s not about Cold wallet mate! Cold wallet isn’t up for discussion so far the standard still exposes public keys when transactions are made and AFAIK, Cold
Wallet Storage isn’t same as dormant, it doesn’t mean transactions won’t be carried out either the only difference with hot wallet is just that the important part of the transaction is carried out offline and the wallet it self never connects to the internet making it have a storage which is “cold”

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I get your point aswell, but you need to understand that public keys is no different for whatever storage you choose and will always be exposed whenever you send Sats out, doesn’t matter if it’s cold or not and the moment you use such address again then your Sats are at risk and again doesn’t matter if it’s cold storage so it’s not like there’re some public keys that will be immune to such attacks when the time comes so far with the current standard.
I saw same mistake from dullen007 post just right after my post , I didn’t correct it because he’s a newbie and will probably realize it overtime what he said was wrong if he’s truly interested in learning..
For the part I ruled out, that’s not even near to being true.. The Particular QC you mentioned is IBM Condor and it’s been available since 2023 but error prone which makes it less performant even with the high qubit count, after that year another QC was being released in 2024 which has lesser “quantum-bit” count compared to IBM Condor but performs better with low error rate.. you can browse it..