I don't know how to rigorously verify who their actual users are on the ground, but it seems like that's at least nominally their target; https://www.mozilla.org/en-US/ says,

> Firefox: Get the gold standard for browsing with speed, privacy and control.

I hadn't actually seen that when I wrote "power users and folks who care about privacy and control", but that's even mostly the same words, let alone intent.