Right, but I think the overarching point is that 3% is awfully close to the 1% that is Internet Explorer, which many would consider dead. If usage decline continues, it just wouldn’t take much for no people to stop supporting it.
If the company behind it dies then development on it will likely drastically decrease and it will quickly become a less attractive option. There's probably a reason why you chose Firefox over any number of other open-source browsers that don't have much development activity.
This is from someone who uses Firefox