I guess, you are referring the sidebar widgets. You have Welcome, Subscribe etc widgets in the sidebar.
Mobile devices have very small display. On small displays, theme focus on the more important part of the website or blog i.e. content. Content should remain in focus regarding to user, search engine and SEO point as well.
It is not possible to align Content and Sidebar, side by side on the small viewports.
I hope, it will help you.