Firefox lost market share because they kept antagonizing their users. It's easy to read Chrome as the boogeyman to blame for Firefox' failure, but that's... also not correct.

Mozilla is, rather frustrating for those that lead it I'm sure, chosen largely based on principles that people found they couldn't get from Google. Things like "don't profit from me the user", "don't track me" and "don't do things in my browser without me knowing about it". These aren't things people point towards the Chrome browser with because if you expect any of this to not be done by Google, then you're kidding yourself.

Mozilla meanwhile has a pretty wide history of just... doing things that break this promise[0][1][2] (listed is mostly recent stuff, but they have been doing it since forever, going back to the forced Pocket integration).

Chrome users don't care about this stuff (since they already use a Google product), Firefox users by virtue of picking Firefox did. And when it comes to optimization, Chrome does beat Firefox pretty handily, so people started abandoning Firefox because at that point, both Mozilla and Google offer the same value proposition.

Their recent ventures into adtech are probably going to annihilate their biggest potential userbase gain, which is Google tightening the screws on adblockers and uBlock Origin in particular not playing ball with them on it. (UBOL is a joke and the UI by design makes it look like a "kiddie"/unprofessional adblocker.)

Google didn't kill Firefox (they want it alive to avoid antitrust lawsuits). Mozilla did.

[0]: https://www.theverge.com/2017/12/16/16784628/mozilla-mr-robo...

[1]: https://news.ycombinator.com/item?id=40966312

[2]: https://news.ycombinator.com/item?id=41497051

Tell Mozilla: it's time to ditch Google