Market share doesn't equal irrelevance as others have said. I use Librewolf and without Firefox it wouldn't exist. It likely wouldn't exist at the quality it is without Mozilla taking Google Cash either. But it's super important to have an alternative even if most people don't use it. It DOES provide a limited check and balance against google doing whatever they want with the web because if the right people make the right noise then people will move over to something that's easy, convenient, and free of whatever pain in the butt google puts in chrome that sends people over the edge. See Linux desktop and Valve for an example of how a software with very few users comparatively can force a larger company to play ball. Remember in Windows 8 when MS basically banned 3rd party software stores on the OS.. or tried? And Valve made the "Steam Machine" and SteamOS? Everyone says the steam machines failed but they 100% did everything Valve wanted them to do. It was enough to have MS go back on their walled garden and allow Steam to keep operating as it had been. And now we have the steam deck on top of it.

So, it's ok if Firefox has a small market share as long as it remains a worthy competitor.