Unity Terrain GameObject versus Custom Terrain

I was recently exploring and working through parts of Sebastian Lague's Procedural Landmass Generation series. Absolutely excellent series and I would recommend it to anyone looking to learn more about Unity and Terrain in general.

Anyways, I ran into a question that I can't seem to get an answer to. In his series, he walks the viewer through the process of making a Terrain asset in Unity from scratch. Therefore, almost entirely within your code, you're adding a mesh, textures, and adjusting the height and colors of the Terrain. All of which (correct me if I'm wrong) you can do with the Terrain Component on the built-in Unity Terrain GameObject, as seen in another tutorial I'm following (Penny de Byl's Procedural Terrain Generation with Unity, also a fantastic series that I would recommend).

So this leaves me with the question:

What is the benefit of creating Terrain through these methods (Sebastian's methods) as opposed to working with the Terrain GameObject/Components (Penny's methods)?

Lastly, I actually posted this on StackOverflow first but have not gotten an answer yet. If anyone thinks they have the right answer and also utilize StackOverflow, feel free to answer the question there well. Thanks!