The decline is exacerbated by mobile. It's become the dominant form of using the web, but almost everyone uses the default that comes with the phone and Firefox

The decline is exacerbated by mobile. It's become the dominant form of using the web, but almost everyone uses the default that comes with the phone and Firefox is nowhere to be seen. Additionally it's been on the decline even with the developer population, my guess is because Chrome and the team around it has been much better in explaining how to e.g. write better performing code and critically how to actually use devtools to measure. Anyway, I think Firefox is toast mostly because of its leadership which seems less interested in actually doing something interesting, and more interested in draining what's left until they can stick a fork in it.