They wanted a browser they have full control over. And you can move much faster when you don’t have to negotiate every change with third parties. Also, Firefox 1.0 and Chrome 1.0 were released within months of each other (though Firefox 0.x had existed for a little while), so Firefox wasn’t that established yet. The main competition at the time was Microsoft Internet Explorer with over 90% market share.

I'm fairly sure pretty much everything at google since the doubleclick acquisition has been a loss-leader in order to give users good 'viewers' for advertisements, there's some nice byproducts along the way of course.

> They wanted a browser they have full control over

Yup and they got it. Now we see them using that power and market dominance to further their business goals with their attempts to kill Manifest V2

Firefox 1.0: 2004 Chrome 1.0: 2008

Whoops, you are right, I misread one source.

You can read the comic that explains some of the reasoning here: https://www.google.com/googlebooks/chrome/big_00.html

IIRC one of the biggest reasons was a single misbehaving tab in Firefox being able to take down the whole browser.

They didn't build it from the ground up but used WebKit.