@Noobienomore - yes, that's totally standard for the battery in an integrated device.
It's a lithium ion cell in a polymer encasement.
There's nothing true horror about it...
Here's one inside a vandy vape simple EX:
They use the same thing in the aspire spryte, and the smok nord, and the sigelei odo.
Oh, and inside phones that don't have user replaceable batteries. And tablets.
And inside my shaver and our electric toothbrush and the wife's headtorch and my Bluetooth headphones and MP3 player.
Basically, just about every rechargeable device that uses an integrated li-ion cell that's not designed to be user replaceable will have a soft case.
It's not just about cost though, it's about size, and about weight - and the soft case cells pretty much always have flying leads so you don't have to spot weld connections or rely on spring/push contacts.