It's an Apple device, what did you expect?
The thing even has an external battery pack, and instead of using USB-C so you could use any power bank you already own, they designed a completely new proprietary connector. In 2024.
Who the fuck does that anymore, except Apple?
You can use any USB battery with it, just plug it into the battery pack. Why? Because releasing this without a battery and leaving it to the customer to source one would be super weird.