2-in-1 laptops: dead battery means the whole thing is trash

I’ve been digging through 2-in-1 laptops—you know, those hybrid laptop-tablet combos—and I'm trying to figure out where people actually buy replacement batteries and what they cost. Let's be real: a battery is a consumable. It wears out, and eventually, you have to swap it. But for a huge chunk of these models, there isn't a single shred of info on where to even find one.

For instance: the Samsung Galaxy Tab, the Microsoft Surface, or the HP Pavilion.

Does this mean once the battery finally dies, the whole machine is just expensive e-waste? Or am I forced to drag it to an authorized service center just so they can rip me off replacing an "internal" battery?