Composer installing two CI4 in the same project?

I started a new blank project (just for testing purposes) to see how to use CI4 with Composer. I then followed the instructions from CI Installation page by typing in the command prompt from the XAMPP htdocs folder:

Code:

composer create-project codeigniter4/appstarter test-project

After a little while it created the structure, but I am puzzled with the fact that I have the CI structure DUPLICATED. I have the four folders (app / public / tests / writable) plus the spare files at the root of my project and also within vendor/codeigniter4/framework. The only difference is that I have the system folder within the vendor/codeigniter4/framework but not in root.

I made a quick test by simply copying-pasting a controller and a view file into both app existing folders and did in my browser:

Code:

http://localhost/test-project/public

I could bet that it would work in the vendor/codeigniter4/framework/ and not in the root because this is where the system folder is, but for my surprise it was exactly the contrary: it worked for the root app but didn't for the vendor/codeigniter4/framework/, making me believe that the root app folder is the one I want to use for develop my site.

I have another CI4 project that I created manually by unpacking the zip file I downloaded from https://github.com/codeigniter4/CodeIgniter4 and in this one the system folder is at the same level of the app folder (there is not any vendor folder because I didn't use Composer).

OK, I could just look to the other side and happily start to write my site in the root app folder but I really don't feel good using something that I cannot understand. Also it doesn't look right to me that:

1) There are two almost identical CI4 structures in the same project; and
2) The system folder is NOT where it apparently should be.

Could someone please explain me this mess?

Recovering the wasted time...