Tl;dr: Google needs to fund Mozilla because there are no other internet browsers available; suitable for todays Internet standards. Microsoft gave up, Opera gave up and Webkit is the only other and it's now iOS exclusive. It failed as a desktop browser.

Without Firefox, Alphabet would be liable to an anti-trust lawsuit. Apple not so, because they keep it to their iDevice.

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Firefox is Mozilla's and Mozilla is a non-profitable organisation.

The story as I know it is that in the early days Mozilla became the defacto internet suite as they produced a suite of applications. Email, FTP client and a browser and these were crafted and sustained by volunteers. (This is skipping the predecessor, Netscape).

The internet was simple then. HTML and CSS with an lil' bit of Javascript made the internet fine.

Everything was open and the rainbow coloured fence of your neighbour was pretty. You could even implement your own renderer and know it would work.

In the dozens: https://eylenburg.github.io/browser_engines.htm

Introducing Google: they started out just as search engine and that it was. Pretty great at it what it was and their was no other. It's boasted feature was one of that you could rank pages with PageRank although in the long run became unprofitable.

The popped dotCom boom had made VC's scared to invest and Silicon Valley was still recovering from the aftermath.

Unlike Yahoo, Lycos and other service providers, who all had offered services like email and entertainment subscriptions, survived.

Google, as bankruptcy neared had offered to sell to Yahoo for $500k and what a different world we would be in. But this didn't happen.

Google then started their up-taking. By introducing advertising to their search engines.

The gimmick I recall is "buying nukes" as if you searched "nukes" you'd get a banner in the right hand side of the page of "buy nukes on ebay". Geeky college humour.

Eventually, they branched out releasing gMail with beta invites and insanely large inbox sizes where the latter only gave you small amounts of 20mb.

And folk flocked to this service. You didn't need 1gb of email storage but hey, you had it. They had it all, a feature rich simple email client. Simple being the key, Simple search engine and your simple website now possible to be seen. As well as vendor lock in. As to change email is as painful to change mobile phone numbers. Dark-UI.

You had a exclusive gmail email, a chance to be on top of Googles search and it thrived. The internet existed but wasn't something for everyday everyone but heck was it a good time.

Introducing Apple and the iPhone. This was the new strike to the internet. The internet wasn't an everyone thing but it was now. Apple created the iPhone from the previous based Java firmware driven non-smart phones with apps and Google introduces with Android a few years later with their apps.

Apple users already being an exclusive clique of the time flocked in masses and this boosted Apple sky high. Eventually major vendors started to suck up to Google as Apple as we know doesn't play ball with the BlackBerry being the business phone, tried! in the end lost as it wasn't innovative enough nor was designed for the consumer market.

We now had this fantasy tech but no future internet for it to work.

And so Google crafted the next-gen specifications for HTML. HTML5 for the internet - This was to enable the "future" and Chrome came with it to carry out these new features.

For their phone and for the desktop web browser prior to that you had Internet Explorer or Firefox. Even then Firefox was least popular because Internet Explorer was shipped in Windows and sabotaged.

This was a further blow for Mozilla because now as an volunteer organisation with less money now had to implement all these new features while Google already had their thing. This kept Firefox lagging behind and made FireFox less popular as the new rebranded Internet wouldn't work with it.

Google with that and advertising money as well as resources could afford to keep implementing, sabotaging and make it painful expiration for anyone to keep up the pace.

While this is excluding Mozillas mishandling and not greatest decisions but here we are now, Google dictating the latest internet splash of paint.

The younger crowds who adopted Google, adopted Chrome as the browser and the legacy keeps going.

Googles vendor lock in for gmail as the same with Canonical's Ubuntu, (which helped Firefox a bit) with its free-cd campaign, and so boosted Linux but ultimately with less money and community support has brought Mozilla to it's knees.