Until I started using Emacs seriously. Now I use Emacs for opening URLs, for triggering Google searches (and saving my searches via org-capture), for saving URLs via org-protocol and org-capture, for taking notes, for journaling, for task management (previously OmniFocus, then Things3), and for all kinds of workflows. It is the ideal application framework, with one of the most versatile programming languages I can think of (Lisp); it made me stop using Python for my day-to-day scripting (love Python!).
Emacs (and Lisp) is a tool for the next decades of my life.