If I understand you correctly....you get some high quality samples, arrange your song..and release...no eqing, compression etc.
Yes, you can do that. There is no law saying you need to mix your songs.
I've gotten samples that work so well in a song I hardly had to make any changes to it. Also, if you are just making a demo and you have no mixing experience then that's fine.
However, if you want to get a song that sounds cohesive and well balanced, chances are you WILL have to do SOME mixing. Even with high quality samples you will have frequency clashes between instruments and useless sonic information that should be removed ideally. There are a lot of intricate subtleties we take for granted in music. Engineers spend years tuning their ears and learning the tricks of the trade. Its an art that can get quite technical. Your favourite songs were not thrown together carelessly, but each sound was molded into something that complements its sonic neighbours.
If you are new to this and the whole idea of mixing seems difficult to learn, well its not - if you are having fun doing it.