The English article for "let it rot" (or a related phrase) seems to be here: https://en.wikipedia.org/wiki/Tang_ping

In my interpretation, 躺平 (tang ping / "lay flat") and 摆烂 (bai lan / ..."let it rot" I guess) overlap in meanings in the "do nothing" aspect, but in the tang ping / lay flat case, it is out of learned helplessness / nihilism, while bai lan / let it rot case, it is out of purposeful negligence / noncompliance, which suits geohot's vibe