A long time ago Mike Lischke wrote a great Delphi component—Virtual TreeView. He stopped supporting it a long time ago, but the component found a new sponsor and a place on GitHub: https://github.com/Virtual-TreeView.
Virtual TreeView supports the VCL framework in Delphi XE3 and later. There are also versions of code that support older Delphis, but you'll have to look around for them. To use it, you have to download the source and recompile two included packages. That will add three new components to Delphi. This example will use the most useful of them, TVirtualStringTree.
Alternatively, you can install Virtual TreeView with the Delphi's GetIt Package Manager if you are using Delphi XE8 or newer.
The VirtualTree demo compares ...
