Iphone findable after power off doesn't really work

I had an iPhone 12pro and it updated to 1OS16 at the time it was stolen 2 days ago. I was happy to discover Apple had a "device still findable after power off". I know for a fact it was enabled because I checked and because had my iPhone 11 Promax stolen earlier this year so I wanted to take extra precautions.

A pickpocket had stolen my iPhone from my bag as I was leaving the subway 2 days ago, I immediately ran home to track my phone from the "Find My" app on my MacBook. However, It only showed the last known location before it turned off and when I log into icloud on the internet it just says "device offline". But isn't the whole point of the feature to track a device when it is offline and turned off? this feature does not work at all. I cannot track my device unless it is connected to internet? what's the point of the feature then! Find My is still the same useless app it has always been. It doesn't even send a notification when the device is turned back on and last location has changed, I have to keep constantly checking when can get tedious.