Bikes are a high theft item. Once a bike is stolen you won’t get it back. I keep my bike locked up with one of those fancy kryptonite U bolt-locks inside a locked shed. I am sure someone could take it anyway but it would be difficult and time-consuming.
My bike isn’t particularly valuable but it does get noticed. I used to ride a bike that was mostly made out of spare parts from other bikes but last I heard it was stolen out of a garage The garage was locked but the bike was not.
Bikes have been stolen from locked cages and storage areas in parking ramps. If. you live in a condo with a storage area for bikes, lock your bike when it is in the storage area.
It is a good idea to lock your bike to something. Like a sturdy wood beam or a pipe. If none are available just use the U lock. The bike could still be stolen but it would have to be carried away and the lock would have to be sawed off.
Keep in mind that there are thieves among us and they really want to steal your bike.
I like my bike. I keep it locked when I am not riding it or taking pictures of it.