I think you’re missing the context. We’re not talking servers here but desktops. Arch is typically used on desktop systems. The threats that face desktops and servers are not the same. Same goes for risk and potential damage. Also please provide a source if you’re trying to debunk “common misconception”.
I don’t like this but it’s gonna take more for me to switch. I am very happy with Firefox for my use-case and workflow it works really well. However I think they are shooting themselves in the foot by starting to take away some of the most crucial advantages with Firefox compared to Chrome. I mean if both are awful for privacy then why use Firefox?