Firefox 73.0

Their marketing has been focusing in privacy and freedom, but their development efforts have focused at least as much on enterprise deployments and management, which includes complying with regulatory requirements and offering lots of hooks for internally modifying the browser.

Firefox 67 improved keyboard accessibility of the toolbar UI, another accessibility requirement that was probably mandated on a regulatory sheet somewhere [1], Firefox 68 added a bunch of new enterprise policy toggles [2], Firefox 69 made the macOS binary signed (they specifically advertised this as a way to help people who use automated tools to provision macs), Firefox 71 added kiosk mode, and Firefox 72 added security.osclientcerts.autoload.

Why did they ditch IRC? Enterprise firewalls block IRC ports. Why does Mozilla want HTTPS everywhere? They don't want middleboxes to be the tool for enforcing policies; they want policy enforcement to be done directly in the browser where they can offer product differentiation. Firefox also wants ad blocking to be done in the browser, because it gives them product differentiation from browsers that can't offer ad blocking at all (cough, cough, Chrome). Firefox does not want the browser to be replaceable, no browser vendor does, in spite of web page authors who very much want browsers to be interchangeable cogs in a highly competitive market [3].

Mozilla will undermine your privacy, as long as they can give it back to you again in a way that requires you to use Firefox specifically. This sounds like a bit of a conspiracy theory, though there's no actual need for anyone to plan it this way: it's just how the incentives line up. Just like Google has no institutional drive to support uBlock Origin, and this causes support for the interfaces that it needs to rot away, Mozilla has great reasons to support uBlock Origin, because it can be a potential reason for someone to use and contribute to Firefox.

[1]: https://support.mozilla.org/en-US/kb/access-toolbar-funct...

[2]: https://github.com/mozilla/policy-templates

[3]: https://www.joelonsoftware.com/2002/06/12/strategy-letter-v/