Almost definitely for import tax/restriction reasons. Putting the battery inside a cheap flashlight places it in a separate category than a battery by itself. Felt on the bottom of Converse sneakers to classify as slippers is a classic example of this.

The battery limit described is for individual passengers, not air freight.

Air freight for Li-ion batteries is pretty strictly regulated too, especially when the freight is carried on passenger aircraft.

See UPS Flight 6 for a very good reason about why the flight of lithium batteries is regulated

As always, Admiral Cloudberg has a deep-dive into this crash: https://admiralcloudberg.medium.com/alone-in-the-inferno-the...

Slightly off topic, but she does an amazing job.

I watched both Mentour Pilot and Green Dot Aviation's videos about it. Mentour Pilot's video terrified me, as it simulated the audio of being inside the cockpit, with GPWS, fire warnings, the sound of the fire all going on at the same time

Green Dot Aviation: https://www.youtube.com/watch?v=T7uw6VzWHcM

Mentour Pilot: https://www.youtube.com/watch?v=Y50saxfTqQA

Yup, any time I order anything from Amazon that has lithium it comes with a big warning sticker about shipping restrictions. Even if it's a fixed battery inside a device.

Indeed. If it’s sold as already in a device, it doesn’t need the battery sticker and in general the regulations around shipping it are significantly less onerous.