Though I'm sure it's much easier to recycle those c grade batteries directly after they are sorted out after production, instead of when they are inside an old vape, inside a container with all the other trash.
This is the dirty secret regarding lithium cells.
At the very least, using C grade cells in this manner ensures a working product gets used for some application even if it is disposable.
Take solice in the fact that when you throw batteries out in landfill trash that most are picked up by high powered magnets and are separated out for recycling.
I find it immensely telling that the vast majority of these things (ie. the popular flavoured kinds) are banned in the country that produces them.