Some people prefer one large PR over many smaller. Indeed, splitting task to tiny atomic contributions takes time. However, reviewing small PRs is typically faster¹ so overall you might ship your entire task faster.

¹ On the other hand, the smaller the PR, the more comments and reviewers it attacts... 

 @0ddf8ed8 The "small PR" effect is, of course, another manifestation of Wadler's Law.