They are looking at OperaGX and Brave selling literal spyware and still growing marketshare and correctly recognizing that the only people willing to switch browsers in the current day do not give a shit about any of that stuff and are weirdos looking for "features"

Look at all the people in this very comment section insisting that Mozilla is just the worst while using fucking chrome or chromium. Mozilla knows they will never get that market back, because that market just hates Mozilla for "reasons", usually "They fired a guy for being openly hostile"

The thing google did to cause the demise of firefox was pay to bundle chrome with tons of things users installed, and put a giant "Install Chrome for BEST EXPERIENCE" banner on every single page they control. Sane governments would have broken them up for their clear anti-competitive practices, but at the same time the vast majority of the users they "lost" never knew they had firefox in the first place and didn't notice when it got changed.

These users never even noticed when conficker changed their browsers to literal adware FFS, they certainly didn't "Choose" a browser freely.