Thanks all, lots of good points. Taking them in order:

Agreed, and nc50lc put it well too. A broken RNG or a non-deterministic nonce is the real bug, and RFC 6979 (and BIP-340 for Schnorr) is what made that class rare. The chapter's narrower point is that reuse is what turns one bad signature into "everything at that address," instead of one payment.

You can, and most setups already do: any HD wallet hands out a fresh address per request, and a merchant server like BTCPay makes one per invoice. For the cases that really need one public identifier (donations, a signature in a profile), silent payments or an xpub on your own server give payers a fixed thing to pay while every payment still lands on a new address.

Fair, and nobody needs to pester a manager every week. Treat the campaign address as an inbox: let payments land, then move them to your own wallet in one transaction (coins from that address only), and never keep savings there.

Good suggestion. Short version: replace the published address with something that hands out fresh addresses (silent payments code, BTCPay, or a Lightning address for small amounts), then keep watching the old one for a while, since saved addresses keep getting paid. Peter Todd's warning about static addresses with no expiry is in the chapter for exactly this reason.

That phrase isn't in the chapter. The advice is the narrow one: stop using the reused address, and if it still holds coins, move them in one transaction to a fresh address in the same wallet. No need to migrate to a new wallet unless your seed itself is in doubt.

Good addition. A visible, long-lived address is also what makes look-alike "poisoning" addresses worth creating. One more reason to copy addresses fresh from your own wallet every time.

When you use wallets and addresses, you will possibly leak your privacy, not only security of wallets and fund. For your wallet security, firstly it must be from security of your devices. Because if you use an infected device for creating your wallet, there is high possibility that your wallet will be known by hackers. When hackers take action to steal your coins will depend only on them, you can not control their action or avoid it.

If the device is clean and secure, you will have to do next steps with your wallet, how to download it, verify it, install it, then create and use your wallet. In practice, how you use address, change address, use coin control, choose UTXO for your transactions together with your practice online and offline elsewhere will contribute to your Bitcoin privacy and privacy in general.

Keeping the key offline protects you from theft, and that's the most important part, agreed. Address reuse is a different problem though: it's mostly about privacy. Anyone who has paid you at that address can see every other coin that lands there and where it goes afterwards. An offline key doesn't change any of that.

On replacing the seed every two years: it isn't wrong, but it isn't free either. Every rotation is a full migration. You pay fees, you link all your coins together if you sweep them in one transaction, and you get a fresh chance to make a mistake with the new backup. It's worth doing when you have a reason, like a backup someone might have seen or a device you no longer trust. If the old backup is still safe, the calendar alone isn't a reason.

One upside if you do rotate: moving to fresh addresses hides the public keys of any reused ones again, so it's a good moment to stop reusing.

Those airdrops aren't really dead, they are not so popular as they used to but they are still happening under the radar and people are still making money from them, it's not been taken very seriously like before but they are still happening.

The only sane way and reason why I can keep to using different bitcoin wallet every time is if I use hot wallet to gather alot of Bitcoin at first  then I move the coins from the wallet to a cold storage or hardware wallet.

I hate using different wallet addresses every time that I want to withdraw from one wallet to another or from a crypto exchange, reusing same wallet address looks so harmless I'm not going to lie but on the long run you are ruining your privacy.

It's not too hard thing to learn and apply for our practice.

Since a time people realize that "Privacy matters" and how they can maintain privacy by using change addresses, coin control, UTXO control for their Bitcoin transactions, they will do necessary steps for their practice and achieve good privacy.

It's a little bit challenge for a first time of learning and practice but it's not impossible thing to learn, especiallly if people value their privacy.

They already have very good available tools for privacy: Bitcoin blockchain, Bitcoin non custodial wallets, coin control, the rest is up to them using these things well and privately.

Security and Privacy Encylopedia.

Not as if they've an option in changing it like Bitcoin wallets have. I'm sure if they do, there are those who would not be reusing same addresses.

But isn't that the main strong point of the Blockchain? So that transparency is maintained? Anyway, if we truly worry about all that, it means that signature campaign participants ought to be alarmed as most of us hardly change addresses until a campaign runs to an end. Some even still reuse same address for fresh campaigns, going on.

With analytic tools available to anyone to data mine whose address belongs to who, I second this motion , but it's not practical with how we use addresses here on the forum, for example we stake addresses which are almost like a tattoo that can't be deleted, custodial exchanges don't make it possible to generate new addresses probably for security reasons to avoid weak entropy and all that..if we talk about sigs this would be too much work changing  Addy's every week, otherwise for privacy concerns changing a receiving Addy is a must to avoid social engineering attacks and all that.