Who cares? I use Firefox but why do I care if the US government does? I thought they were still using Netscape on Windows ME
Did you read the article? This is about how the government’s web developers could stop writing websites that support Firefox. You might have to switch to Chromium to use government websites.
Web dev here. Unless they explicitly block other browsers or somehow adopt bleeding-edge tech that other browsers have and Firefox doesn’t (has Firefox ever not been the first to support new standards?) I don’t know how this would even be a problem.
When I worked for the USDA in 2010 we had several web applications that depended on Internet Explorer 6.
I worked in an office in 2009 with a Windows 95 PC (a Packard Bell that barely ran the OS).
I got them to upgrade it in 2012.