> Firefox usage share grew to a peak of 32.21% in November 2009, with Firefox 3.5 overtaking Internet Explorer 7, although not all versions of Internet Explorer as a whole;

Firefox was the browser that embraced open standards and was unseating IE. And ActiveX was used for corporate stuff, not general web sites, so the main reason it died was that Microsoft gave up.

There was a good, long period where Microsoft just decided to let the market run amok with malware for critical software, instead of providing something like Preview on macOS. As a result, the safest option for most lay people was to use Chrome, where they could quickly and easily view, and most important, save pdfs of websites, receipts, etc.

Then, once MacBook Airs were solidified + iPhone, I started recommending people use macOS simply because Preview could edit PDFs and easily allow signing them.

I haven't used Windows in a very long time, so I assume it's still the same situation.