Not everywhere. In Sweden that would be a crime (a little bit depending on what you mean left in the open).
So stealing your own thing back without the police involved may technically be illegal, but practically if the airtag tells you where your stolen bike is and you have the keys, skip the police and take it. Nothing will happen. The thief or their client is not going to call the police since that gets them arrested or fined.
Of course you can't go into the thief's house to retrieve your things. Then you do need to call the police first. But the one case I know about someone doing that for a stolen iPhone based on Find My app location, the police showed up quickly and arrested the thief + found lots of other stolen things in their possession.
If you buy something that was stolen, the original owner has the right to get it back without compensation to you.
In reality things are not so stiff. My dads bag was stolen from the train. The thief was apprehended on the station. He got his bag back from the cops because it had identifiable information in it. Perhaps a bit light on evidence that the thief was not the owner, but it's not always overly complicated. I think the thief got the right nudge.
A fun thought experiment is that in the time you might have left your car parked in the street, it might be stolen, sold bona fide, then (by happenstance) parked in the same area, so one day you just go back to it and drive it away.
I guess in a more practical sense, you could claim that's (more or less) what happened after recovering your possessions after having them stolen... what would happen in that edge case?
Does not change anything. I mean poor guy, became a victim of a fraudster, but what does my bike have to do with it?
>you cannot repurpose the product yourself
This is not repurposing, this is its prevention.
>solutions of real world capitalist conundrums
There is no conundrums, it is pure tyranny.
More broadly I think it does make a certain sort of sense that a theft should be resolved by the police. Find your item and want it back? Get the police involved. It's just that these days we're all so used the police being completely ineffectual that taking matters into your own hands is the only "sensible" solution.