Can say the same thing for other distros. Clearly, I'm not that knowledgable in the Linux scene. They are completely reformatting / removing all datas anyway. They do it manually and it can't be just preference because doing a tutorial, the "Erase Disk" option is much simpler. (Yes I know the manual is easy to do but it is just adding more steps).
So what gives? What is wrong with the "Erase Disk and install X"? The tut videos don't even explain, they just "Don't go for "Erase Disk", click "Something Else" then do this".