12bytes: Note that Firefox sandboxing was strengthened in version 99.
Firefox is sometimes recommended as a supposedly more secure browser because of its parent company's privacy practices. This article explains why this notion is not true and enumerates a number of security weaknesses in Firefox's security model when compared to Chromium. In particular, it covers the less granular process model, weaker sandboxing and lack of modern exploit mitigations. It is important to decouple privacy from security — this article does not attempt to compare the privacy practices of each browser but rather their resistance to exploitation.
Certainly there needs to be more real competition in the browser market beyond configuration files and forks but the problem, because of what the web has become, is that a web browser has to deal with whatever garbage is thrown at it and this requires a massively complex beast with 10's of millions of lines of code, much of it potentially exploitable. I don't think such an undertaking is doable with a small team, hence why i do not recommend Waterfox, Pale Moon, etc.. As such i think it's entirely possible that all future browsers will be delivered by large corporations which, like Mozilla, don't seem to give much of a crap about privacy at the corporate level. While the story is perhaps significantly different at the developer level, for now, i think we can all see a potential train wreck at the end of the tunnel.
As for me, i'm willing to roll the dice and stick with Firefox (and the 'arkenfox' user.js and my custom tweaks) for the time being, regardless of my disdain for the woke clowns which have infected Mozilla.