What you need is something like being able to search all of the cameras from a wide area which contain a bike and x color hoodie so you can follow the person back to some other location that identifies them further. This is the part that's missing in most cities. It could be done manually, and it would be if it was a very serious crime like terrorism, but for normal theft it isn't worth the time. The tech does exist now though.

1. The odds of the actual bike itself being covered by CCTV during the theft is pretty slim. Nearby? Sure, but probably not recording the offence. Then unless you're got a precise time window/know where the thief went, you're stuck watching hours of footage hoping to spot the right bike.

2. Even if you do get a clear, high quality facial picture of the thief, you have no magic way of figuring out who that is. You essentially email it to all the local cops and hope someone's recognises them.

The result is your bike theft turns into quite a big investigate, with a sub 5% likelihood of a position outcome.