In this case, the trade-offs being extremely rare lock picking bike thefts versus everyday bolt cutter attacks.
If you ever suffer the horror and anguish of bike theft, hopefully the thief will cut the last link of your chain and not the shackle of your, hmm, Assa Abloy 330?
It's a Master 1533, which comes in a package of 3 colorful locks with the same combination, and is a smaller version of their classic dial combination lock. I doubt that it's really super secure. The chain would be slightly easier to cut than the shackle of the lock. Either way, I'd be sad if my bike got stolen.
Judging from the locks that people use, bike theft is not a huge problem in my locale. Many people use cheap cable locks.