I'm calling it today: 2017 will be the year of the Firefox come-back. I recently started using it again after switching to Chrome when Chrome was initially released in beta. I'm more of a second-wave of adopters--not among the very first but before the masses jump on board. I predict that tech-savvy business users will start jumping back later this year and that by 2018, we'll start to see non-technical people (like my parents and in-laws) start to use it as family and friends begin to recommend it.
Why? Battery life and speed. Chrome is just a mess these days. Absolutely terrible on laptops.