How long can you track a Pixel after a thief has powered it off? I tested it to find out

TL;DR: The first test was a total disaster and my phone wasn't located until an hour after it was back next to me.

This is not a feature in my eyes; it's a security and privacy breach.
- First they took removable batteries, then they waited until people get used to it, and now we get this nice feature.
- Look at how it works.
  
  No one knows how it works except Google. Who is a notably untrustworthy source.

Wouldn't phone thieves also be using blackout bags anyways?
- If they are professional and not someone looking for a quick buck, and professionals probably wouldn't steal a random person's phone
- What is this and where do I get them?
  
  Bag with foil or mesh lining that turns it in to a faraday cage.
  Amazon and other similar marketplaces have them.
  
  Bag that effectively blocks any kind of radio signals such that they kill communications with any device you put in them.

I really wonder if testing in Europe could be part of the issue. In the US, everyone is a privacy moron and leave things wide open. Elsewhere, people are more conservative about sharing location in general, let alone joining a "community-supported" device location mesh network. (Google's and Apple's are also separate "networks" and don't share, other than being able to both track AirTags and similar trackers to report stalkers.) They also aren't as frequent to have the latest and greatest phones/devices elsewhere, as American corps all rig up loan pyramid schemes to push units as frequently as possible.
Apple customers also tend to be more trusting of that 100% closed-box company's software, it's completely possible more people have that feature turned on, making it more functional (and with Apple's dark patterns to trick users into re-enabling features, they may even be unaware it is on.)
The article author could have done a little more minor technical diving as well, using LightBlue Explorer on an Android device to find the MAC address being transmitted when the phone is turned off, and then look for it later.
Apple's devices when using their "Find My" network, while off, actually start using a different Bluetooth MAC address than when the device is turned on. Android's may behave similar.
Gotta say, this is one thing I miss on most review sites these days. They're so basic, they do the bare minimum, very little black-box engineering, very little sleuthing. It's more important for them to receive free demo units from the manufacturer than to do actual tech journalism.

Aluminum Foil has joined the chat.

How does this feature work? Is there a separate small battery just for this purpose? That's horrifying.
- I know nothing but in my head I imagine this feature works by having the phone going into "air tag" mode when powered off. Same battery, low power chip running minimal BLE to broadcast a tracker ID.
  Edit: after reading the article, both Apple and Google promise their feature works even with a dead battery, so probably a secondary rechargeable coin cell with the "find my" chip. So basically it's got a built in air tag with a much shorter battery light
  
  Yeah, I don't like that. I see the benefit, but it's a real gift to authoritarians too.
  
  No it works by simply putting the device into a deep sleep mode. Watch a disassembly video for any modern phone and you won't find any secondary batteries. The thing is a "dead battery" is not really dead, the device will just shut down before then.