I'm not buying that at all...

First of all, there's a wide range of DHVs sold with removable 18650s that are made by Western manufacturers

Arizer, tinymight, davinci, potv, etc.

Hell, even Chinese manufacturers like xlux/xmax have a separately registered company in the USA, and all of their products have replaceable batteries.

And vapes need quite a bit of power, which battery sockets are not rated to handle. So built-in batteries with welded tabs, soldered (or screwed) to the PCB, are kind of the only choice for the engineers designing these devices.

Secondly, nic vape box mods draw at least 2-3 times more amps and are still sold with removable batteries.