> An additional benefit of isolating the account is it would help to limit damage if it gets frozen and cancelled.

you end up on the fraudster list and it will follow you for the rest of your life

(CIFAS in the UK)

Sure, if the bot is actually committing fraud, but there's perfectly valid use cases that don't involve fraud, e.g., buying groceries, booking travel. And some banks provide APIs, so it's allowed for a bot to use them. However, any of that can easily lead to flagging by overzealous systems. Having a separate account flagged would give the user a better chance of keeping their regular payments system around while the issue is resolved.