You could do it with humans - every time you click "mark as spam" it doesn't just trash the email, it begins a long and drawn-out chatGPT conversation with the spammer, stringing them along.
Look up 'pig butchering' when you get a chance. It is an elaborate process of convincing your mark to fall in love with your persona and asking them to send it money. It takes months to years to execute but marks end up losing their properties, retirement accounts, life savings, everything to it.