As you mentioned in another thread. You came from Bukkit. Here with Sponge you will find things to give you more options.
If it were like what you want. Aka the following code
String id = stack.getType();
Then how would I get the item types name? The only logical thing I can think of creating another function to get the display name, but then you have 2 or more functions refering to a single type that isnt really directly related to the object. Thats why these are grouped together in there own object that can be retreived from the original object. Yes its slightly more work but it makes everything a lot cleaner to write and believe me, it doesn’t take long to get used to, so much so that when I write a bukkit plugin now, all i see are things that need to be changed or even added.