Many traditional types of payments, such as wire transfers, cash etc. are also non-undoable. Incarceration and a variety of other tools at law enforcement's disposal are used to recover funds.

Those payment instruments are generally subject to fairly low transaction limits due to the potential for abuse. Cash is the exception there, but it's extremely inconvenient to move or store large sums of cash and nearly impossible to do so anonymously.

Crypto is unique in that transactions are immutable and do not scale in difficulty with the amount being transferred. Ransomware gangs do not choose to accept cryptocurrency payments because it aligns with their politics; they do so because it is the only way to move millions of dollars across international borders in an undoable fashion.

Those transactions are still undoable by a third party. Using the legal system you can file lawsuits and the perpetrator can have the cash or electronic debits removed without their participation.

With crypto, you must have the help of the criminal, because only they can unlock the wallet.

There are many ways to implement undo-ing transactions on the blockchain. One is with multi-sig wallets.

There are also others: https://www.coindesk.com/tech/2022/09/28/stanford-proposal-f...

You keep talking about "multi-sig wallets" in multiple posts. Are you going to have courts in every relevant jurisdiction have a handle on that wallet? That seems unlikely to go over well with the sorts of people who take these seriously.

I don't know, that's a good question. That's the discussion we should be having, instead of flat out stating that it's impossible.

The "sorts of people who take these seriously" will never be happy, so that's fine.

One should demonstrate an actual, tangible, serious raison d'etre that is within the bounds of the modern legal system before bothering to find out if it's plausible.

One still does not exist for cryptocurrency.