Getting back to the article is cumbersome due to the small target
This issue concerns the target area for closing the left menu.
Launch Wikipedia on Mobile
Invoke the left menu
You will see a white panel which is a portion of the article on the right.
At some point the user may want to simply get back to the article they were reading.
In order to get back to the article the user must click on the hamburger menu which is 50px X 50px only.
The design pattern here is that clicking anywhere in the white space must collapse the menu.
This is an established design pattern on Facebook web app, Facebook Native app Path and some other popular apps and users have an established mental model around it.
Clicking anywhere on the white article portion should collapse the left menu and allow the user to get back into the article.