In a cheesecake, what’s the purpose of creaming the cream cheese and sugar? I did a cheesecake following this recipe (first time).

I didn’t know I had to use cream cheese at room temperature, so I took it directly from the fridge, and also I don’t have an electric mixer. So as you can imagine, it was extremely difficult to "mix cream cheese with sugar until smooth". I decided to give up on that mixing and just continue, given that with the eggs and the milk it would be much easier to mix.

In the end, I got something which looks like a cheesecake (the texture is uniform) and seems to taste like a cheesecake (not that I have much experience), but is very dense and I feel that my stomach has trouble digesting it.

Looking at the Internet, everyone says that it’s important to cream together the cream cheese and sugar very well, which I didn’t really do, so I was wondering what’s the purpose of it? Would it explain the fact that my cheesecake seems a bit too dense?
Creaming the cream cheese (fat) and the sugar grinds the sugar crystals making them smaller and also puts air in the globules of fat. Later when you bake the final mixture the air pockets expand making the baked mixture fluffier (increases rise...).