I've never been wealthy enough to insure my belongings, so my experience with trying to make police reports for theft have not only felt like a waste of time, the officers I've filled with have directly told me I'm wasting my time (and implied I'm wasting theirs) whenever I have made a report.

In the US, it is common to carry renter's insurance. It covers liability you as a renter might have for damages to the landlord's property such as water, fire, or other kinds of damage. It also usually covers your belongings as well. That coverage usually applies to your belongings regardless of where they are and covers things like theft. Bike get stolen from a bike rack? Backpack get stolen from a car? Usually covered, with deductibles, of course.

A lot of people I know who carry renter's insurance were unaware it covered their stuff like that. YMMV on what is and is not covered though.