The pen-style batteries charge from USB and are as easy to carry around as a pen or, say, a lighter. Do you normally light a joint and discard the lighter? Are you carrying around one strike-anywhere match per joint?
The user pushes a button, breathes in some vaporized oil, and puts the battery back in their pocket or bag. It takes about four seconds. A user could do this in a bathroom, a confessional at church, on a bus or on a train.
It is much easier than setting something on fire, passing it around while it's burning, and then putting that fire out.
A gram cartridge is about the size of a pen cap, lasts even a heavy user for a week or more, and doesn't make the user's bag smell like weed.
Are you imagining those giant wizard vapes that are the size of a pack of cards?