Why not use currentDirectory instead of directory.FullName for Path.Combine?

In the video, Carling first uses Directory.GetCurrentDirectory() to get a string containing directory's path. She then uses this string to make a DirectoryInfo object and uses its FullName property, which is also a string containing the path.

Could you not just use currentDirectory directly inside Path.Combine and cut out the middle man?

string currentDirectory = Directory.GetCurrentDirectory();
var fileName = Path.Combine(currentDirectory, "data.txt");