Not all bike locks are created equal. If you’re going to be securing even a moderately expensive bike in a theft prone area then get something like this: https://www.uscargocontrol.com/products/9-32-x-2-pewag-secur...

The lock can be picked. And a battery powered angle grinder can cut through the chain. But both will take a much longer time than any u-lock. Meaning your average thief, who’s looking to work as quickly as possible, will move on to a different target.