My bank knows where I live and if I start cashing fake checks they know where to send the FBI.
Even in the old paper days banks where a little hesitant to let me come into your bank with a check from you and cash it without me also being a customer of that same bank. In theory you could do it, but sometimes if you tried you got the runaround.
You can still wreak havoc with the account and routing numbers if you want to - it gets reversed when noticed which is why people still do it - sometimes it’s not noticed.
Even in the old paper days banks where a little hesitant to let me come into your bank with a check from you and cash it without me also being a customer of that same bank. In theory you could do it, but sometimes if you tried you got the runaround.