I feel we are comparing apple to oranges here: sublime (a text editor) will simply list files & directories in the top level folder when you add a folder to the projects while an IDE (thinking mostly of Eclipse here, but I assume other IDEs aren't that different) will parse every single file to build ASTs, symbol lookup tables and all these things that you either love or cannot stand.
With ST3 we scan and index symbols in each file contained in folders that have been opened. This powers our project-wide Goto Symbol functionality and the Symbol Definition popup.
VS Code (a "smart" text editor not to be confused with Visual Studio an IDE) doesn't parse C++ code (which is what Chromium consists off) in the default configuration. And even if you have the C++ extension enabled it doesn't parse any code until later.
