You can assume that this offer is not coming and move on. There's plenty of cases like this, a quick google and you can find them, mostly on reddit and other forums.

I think what's happening is that they are still interviewing people and stringing you along in case they can't find one that's better. ( Note, better can mean many things, could be that someone is lousier than you BUT willing to take 30% lower pay, so this person would be "better" to hire cause cheaper, etc )