Check the difference between block inline and block position. Blocks can't be moved by mouse or possition settings. They can be moved only with arrows on the right side panel. With help of blocks you can build adaptive structure to the different changes on your pages such as multilanguage text when for one language text is longer than for another and it requires more space and blocks position of elements in such cases will keep order of the elements and distance between them and prevent overlapping and misplacing