"It seems the only way to protect against theft is to ride an old bicycle."

Or move to the countryside, where you can usually leave your bike unlocked outside of the supermarket ...

And reading all the bike theft horror stories here, I was wondering, why GPS tracking is not more of a thing? It seems to exist, but might be hard to make use of in reality?

(because professionals jam them or remove them and the police is not too eager to do something about a stolen bike?)