Many of said features are just bundled web extensions, add-ons, so they don't pollute the main code base. Please, don't spread FUD when it is not needed.

Chrome has consisted of significantly (i.e. millions of lines) more code than Firefox has for quite a while now.

I feel like I heard that a Chrome install was comparable in size to an average Linux install a year or two ago.

The features they're 'cramming' into Firefox don't slow down the browser.