Thieves break into cars to take what they can see, and also to try to find something they don't see but which they suspect might be hidden inside. A cargo cover at least eliminates the first motivation, even if it doesn't help with the second. A cover can also protect items from direct sunlight, which in some circumstances might be beneficial.

I’m guessing cars are more likely to be stolen than broken into. As for the cover, I’d get it. Thieves are more likely to steal what they can see. If they see a cover, there’s a chance there is nothing under it and a waste of time for them.

100% depends where you live.

Is it worthwhile having this? Like does having the back obscure my 5 suitcases? Or does it imply I’m hiding something valuable and since no one else is using a cargo cover, it’s an attraction to thieves