I think that's the best opportunity Firefox has.

If they position themselves as THE privacy-first/ad-free browser they could get people back. It would truly be a better experience (specially the ad-free part) which is the only way to get the non-IT crowd interested.

Other features like memory, speed, etc are a commodity now, both browsers are good enough for non power users, but Chrome is stuck with ads because of Google. Firefox is free from this and can use it to disrupt the market.