Why making a Views page instead of Views block?
Blocks are appropriate to display piece of content but a Page is for displaying the whole content. 

If you create a block of a View, using admin UI you can easily place it in any region (or panels) and reorder it but this option is not available if you use Page.

In Panels, if you use Place In-Editor option to build the pages (like the following image) pages will not be available. This is a very powerful tool in Drupal so if you don't use the appropriate structure you will miss it.



So as a result, by using blocks even a regular user can also easily change the structure of the site and no coding is necessary.

If you create a Page display of a View, to display it's result in some section of the page you must use views_embed_view (or similar ones) function to load that View. This function doesn't load the View title, widgets and ... .

You can use 30 variables to store 30 numbers but you can also use an array with 30 cells. Both approaches work but you should use the reasonable one. It is like your question. you can build your site using both display modes but you should use each one in it's right position.