Sometimes, teams can be good defensively despite not having any All-Defense caliber players. Sometimes, teams struggle on defense despite having high-level defenders. The Los Angeles Lakers are terrible on defense and they don't have any high-level defenders. I'll go on a limb and say that's the worst option of the three.
When everyone's healthy, the Lakers roll out a lineup of Luka Doncic, Austin Reaves, Rui Hachimura, LeBron James, and Deandre Ayton. That lineup has played just 85 minutes together this season, so it's hard to determine what's real and what's a product of a small sample size.