摆烂 originated from NBA basketball culture (tanking — intentionally losing to get better draft picks) and became mainstream Chinese slang around 2022. Unlike 躺平 (a philosophical choice), 摆烂 is more about surrendering out of frustration or laziness.
usage
More negative than 躺平. 躺平 is a deliberate lifestyle choice; 摆烂 implies giving up and letting things deteriorate.