I carry my bicycle into buildings wherever permitted, and make full use of the free staffed bicycle parking & free bus whenever possible. I also have 24/7 keyfob access to secure basement parking at my local train station (did require proof of address + one time fee to sign up). See if you can contact your local municipality as they may have something similar in operation.
Before that, I experienced one attempted theft. At the time my bicycle was locked with just an Axa wheel plug-in chain combo lock (very rare in this country) which is built in to the frame.
Came back to see it on the floor with the electronics gutted: no camera, lights, or bike computer. It was dark and luckily I had emergency lights in my backpack to ride home safely. Reported to police, I tracked down some of the stolen stuff online, and even the shop they were sold to (called to verify), provided serial numbers, police did nothing.
Since the attempted theft I use two D-locks in addition to the built-in one, and have quick release mounts on all my bicycle electronics. I miss when I was studying at university and could leave my bicycle outside the library all night with just a cable lock, with no worries