I just activated a gig to write english essays on any area in human physiology; I wonder the kind of response I would get from fiverr buyers.
How gigs fare on Fiverr is largely dependent on how well you promote them outside of Fiverr.
You would be smart to use a marketing plan that includes promoting your services in places where your potential buyers hang out such as various social media, blogs and forums.
Fiverr is like a warm, safe parking space for your gig. If you really want it to go somewhere you have to drive it.