[Macha]

I'd also point out that tabs and adblock were compelling end user features to the extent that nothing any major browser has on its competitors today compare to. Sync is the closest to a compelling killer feature any browser has got to these days, and all browsers had it very quickly (except Safari, which doesn't have to care when you don't have a choice on iOS).

The fact that Firefox was faster than IE and any technical expert you asked for recommendation would prefer it due to better standards compliance/extensions/having the only devtools were really the icing on the cake.

Google also has the kind of trust amongst end users, especially non-technical end users, that Mozilla couldn't hope to have since Google has their hands in so many pies. And as a technical friend/family member asked to make a recommendation, if anything the incentive is to recommend Chrome to reduce tech support calls when HangoutMeetDuoChat/YouTube/Photos/their preferred google product is acting weird in Firefox again.

It's hard at this point to see what any browser could do to build that kind of end user feature lead again this far into the game.