Article seems pretty flawed. Relevance is a vague metric, and the author relies pretty heavily on data related to government site visitation, which seems subject to bias toward certain types of users.
Market share is likely still incredibly low, but Firefox’s relevance should be spiking right now due to Google’s shenanigans with Chromium. The fact that like 90% of revenue for its for-profit wing is from Google is still troubling.
Any alternative views out there?
Peak Firefox was back in 2010/2011, almost 14 years ago, it has been steadily dropping market share ever since. This is not a new problem by any stretch.