I always use Firefox for web browsing and Emacs for text editing and programming. My other application usage seems to periodically switch between three states:
1. everything in the terminal as that's fast and effective (mutt, newsboat, etc)
2. everything in Emacs for the superior integration (mu4e, elfeed, etc)
3. use GUI apps (Geary, Liferea, etc) as they are typically easy to setup, and I need to use what normal people would use in order to promote FOSS usage (and help to improve those tools that normal people would use)
I'm currently in the process of moving from state 2 to state 3. I expect to rotate back to state 1 again sooner or later 🙂