Emacs is not really an editor but more like an editor construction kit. It comes with a half-built editor. It's not a finished program, but rather a full-fledged computing environment, with it's own programming language. When it comes to wrangling text, Emacs is more powerful than everything else out there. By far. It's been around a long time and gives you complete freedom to change it as you need. It can adapt easily and quickly to any programming task, and I'm not referring to syntax-highlighting or command-completion only. It's often the first editor to support a new or experimental programming language, because of how easy it is to extend compared to other editors. But Emacs also knows how to connect to your database and how to evaluate, against a remote server, something you've typed or highlighted. It takes interactivity to the limit, allowing me, for example, to drop into ielm mode and use the integrated Lisp interpreter for exploratory programming, even when the code I'm ultimately writing is in another language.
Emacs has been around since the mid-70s!
A lot of people have used core Emacs capabilities, over decades, to improve the program in a consistent way to the point where out-of-the-box it already has more features than any other such product in the world.
When you start to use a newly installed Emacs (the half-finished editor) for the first time, it seems archaic. It doesn't work like the rest of the apps on your computer and it doesn't look or seem as modern, at first. The key combinations for Cut and Paste that we're all so familiar with today became available in Emacs long before Microsoft Windows introduced Control-C and Control-V, and long before Microsoft Windows itself was introduced. So, you'll need to get used to some new key bindings. In general, Emacs key bindings are better thought out than today's most common key bindings. But these and other issues can give a lot of people a negative first impression of Emacs that leads them to quickly discount the editor.
If this has happenned to you, I suggest that you take a hard look at Emacs again if you want to excel in the field of computer programming. It's capabilities completely obscure the capabilities of all other text editors. This translates directly into a significant boost in your productivity.
I posted this text (or, more precisely, a very similar text) in Reddit r/programming in 2010. It's all still true today.