The short answer is no. The same can be said if you flip the question around and compare non-fiction to fiction.
For some people, writing is “easy” no matter what format they work in – but it is safe to say this is not true for most of us.
As someone who has written throughout my entire professional career – whether for articles, news releases, website content, social media, contract proposals, ads, blogs, speeches, a series of non-fiction books, or most, recently, a novel, I would not say that writing is ever easy. However, there is a certain ease that develops when writing within one style rather than switching between types. In comparing the process of writing non-fiction to historical fiction, for example, I feel both types require the same diligence, research, and attention to detail.
When we were chatting around the dinner table a while ago, a family member commented that it must be more difficult to write historical fiction than, say, biographies. I replied that I felt non-fiction was harder, since in writing fiction, if you didn’t know something, you could simply make it up. In writing non-fiction, however, that is not usually one of your options (generally speaking).
And yet, that was not an accurate reply on my part. In writing historical fiction as I am now doing, I am fully onside (which is to say, I have elected this approach) with being as accurate as possible within the historical period and, as an author, using the imagination in ways that do not distort real events and genuine human interactions in the period. Writing historical fiction is somewhat similar in this respect to writing non-fiction. Expanding outside of the historical fiction genre, it is reasonable to say that all types of writing require diligence, effort, and some degree of research.
In short, whether someone is writing fiction, historical fiction, non-fiction, or some other type of project, the creative act of generating text requires focus and patience. There are no short cuts to writing well. I can also affirm, from years of personal experience, that persistence and practice go a long way towards making writing easier for anyone, no matter the starting point, and regardless of the chosen style, type, and genre.