I don’t know at all, but if I had to guess extension usage is pretty low. I’m not sure the average user really sees browser extensions as something they need. They aren’t as obvious as say mobile apps.
On the flip side, extensions like Honey seem to suggest at least enough people use them to be of some worth.
Some of the more popular extensions have thirty+ million users, and this is for trivial fluff functionality. When you hit up the extensions dealing with adblocking or say, interacting with Instagram, they can hit 100+ million easily.
