What is the tl;dr of the tool? How does it differ from the description of its category, Text Editor?
Sublime Text is a modern editor with support for multiple cursors, themes, macros, helpful shortcuts, and packages created by the community which extend functionality, as well as the ability to build and run code inside the editor.
Why use this tool over an alternative?
Sublime Text's main advantages are being lightweight compared to other modern editors and as its multi-cursor functionality which can significantly cut down time on bulk edits.