Yes, Firefox is good for browsing but as a developer who has to work on the frontend, the ecosystem isn't there in Firefox. Many of the framework debugging tools for React, Redux, etc. don't work well in Firefox.
https://addons.mozilla.org/en-US/firefox/addon/react-devtool...
https://addons.mozilla.org/en-US/firefox/addon/reduxdevtools...
...And I don't really recall many issues.
Ever since WebExtensions, there's not really a good reason for the devtools to be much worse on Firefox.
If you have used these extensions and have issues, I'd love to hear them. I've done React/Redux dev on both and I don't notice things working significantly better in Chrome. (Admittedly, I haven't done any in a few months.)
The only real thing that gets me now is the lack of being able to inspect WebSocket frames. :(