What rapidly declining market share? Did you even open the wikipedia page you're referring to? There are no graphs over the last few months, and if you look at the sources[0][1][2], it looks like their market share declined BEFORE the layoff (from January to August 2020). After the layoff, it seems pretty stable.

As a reference, I'm going to post the values here:

  Source: Jan 2020 - Aug 2020 - Jan 2021
  netmarketshare: 3.61% - 3.00% - 2.98%
  wikimedia analytics: 5.2% - 4.6% - 4.7%
  statcounter: 4.7% - 4.09% - 3.77%

Also I'm actually pretty satisfied with Firefox.

[0] https://netmarketshare.com/browser-market-share.aspx?options...

[1] https://analytics.wikimedia.org/dashboards/browsers/#all-sit... (change date range to Jan 1 2020 - Jan 21 2021, remove other browsers)

[2] https://gs.statcounter.com/browser-market-share#monthly-2020... (remove other browsers)