I have one system I still use chrome on - my late-2013 Macbook Pro.

The reason I use chrome as my main browser there is because Firefox and Slack do not seem to be friends on MacOS. I use slack in the browser rather than the native app and FF seems to get copy and paste functionality all messed up.

I would use Safari, but some quirk of the office webmail (Outlook of some sort) means that email from Safari gets flagged and blocked as potential spam by an outbound mail server :/

But everywhere else, Android phone included, it's Firefox because they don't pull these kinds of shenanigans.