If it was just flowers and bloom, then the thorns would have not grown. If it was just sparkly and shimmery, then the dust would have not shown If it was just sweet and creamy, then why would have bitter existed.
If sky was always blue, then why would other colours printed. If it was all melodious and flowy, then why would have screams shouted. Only kindness and caring was shown, all the believes and truths were ignored, then why would have love existed.