It's all the small things. Till recently there weren't even react devtools for Firefox. Almost any dev-oriented extension targets chrome first. Chrome has a great devtools protocol, and node conveniently happens to support it too, which is also why many node debugging tools will use chrome.

I use Firefox for casual browsing, but all work-y stuff I do in chrome. Sometimes I'll start debugging a site in Firefox and then some behavior is a bit "off" or missing and I just go back to Chrome.

And the only reason I'm using Firefox is because it's not Chrome. I wanted a different browser that looks a bit different to always be aware of the difference between work and personal.