They're losers and they know it
Why else would someone cling so desperately to lies, even when it's easy to see through? Why else would they sink so low and shameful with the way they act? When you're so full of shame that won't leave (sometimes to the point of sociopathy), nothing you do is too low at that point.
Why else would they laugh and think "any attention is good attention, and it's control!"? Because they know the power and control lies within you and the attention you can give. Unlike you, they can't stand alone in the world. They know it.
Let them have your attention for right now, it's ok to relapse or whatever. They need it, until they get their old/new supply source. They were unfortunately emotionally and physically left alone in the world when they needed it the most. (This goes to the BPDs and the BPD/NPD comorbids too lmao, you matter rn, you also need accountability)