Some Level 2 or Top Rated Sellers will have only One 2 or 3 Gigs. Even though they could have created 20-30 Gigs, They maintain only 2-3 Gigs on their profile.
Please Let Me Know.
I think it depends on your Gig niche.
Plus, if you only have the skills for one or two Gigs that you can honestly deliver on consistently, why fill your profile up with filler Gigs?
You don’t gain any more activity by having more Gigs than the next person in line.
I have usually between 7 and 9 Gigs in my profile.
I also go through them at least once every six months and delete the ones that don’t perform and either create new ones or leave them be.
As the needs of Buyers evolve, it makes sense to evolve your offerings to meet the demand.
I hope that helps.
I think you might find this topic interesting:
I am a TRS with only three gigs, so I am one of the people you are talking about. I had only one gig for the first two years of my Fiverr career. Then I decided to create two more as I was always asked if I provided those services.
I am offering these services simply because it is what I want to offer on Fiverr. I could also offer writing, game development, business plans, video editing, or marketing via YouTube as I am skilled in those areas. Some even more so than I am in translation. However, these things I have no interest in offering here on Fiverr. For me, these are strictly skills I wish to use to expand my own personal ventures.
Also, my current gigs are already taking up a lot of hours every week. I am not sure I would have time to eat if I started offering more things.
Finally, I agree with @looseink - there is no need to fill your gig quota with a lot of filler gigs just because you can. You have to be able to deliver professional quality.
I’m another TRS with only a few gigs. They cover all the services I offer. Why make more?
I don’t see a point of creating 20 gigs.
I’d rather offer 3-5 top notch offers/gigs for my clients than running around with 20 different offers
and change your drink? (the cake only once, it was probably yesterday, happy birthday) 
I think Fiverr is promote some gig but not promote all gig is maybe rule
The main purpose to make more gigs is to just show your presence on different keywords. If you make different gigs, then definitely you would be serving on different keywords.
I want to try drawing a Halloween themed shirt/sweater for you and maybe replace the mug with a Jack o Lantern or something 
Or put a silly looking Halloween hat on your head?
You start with zero gigs. So, logically, the question isn’t whether there are benefits to having less gigs, but whether there are benefits to having more gigs.
This will depend on your niche, your goals, your personal preferences. You’ll find successful sellers with few or even just one gig, and such who use pretty much all or all their slots.
The sensible thing from my point of view is to create as many gigs as makes sense to offer what you want to offer - always keeping in mind that Fiverr doesn’t want “duplicate” gigs - at any given point, and to re-evaluate as you go and adapt your gig situation (create a new one, delete an obsolete one, edit an old one (again, keep the rules in mind; giving your gig a new fresh appearance, changing the package structure of what you offer, etc., is fine, but don’t change a gig in a way that your permanent gig URL and the changed gig title, etc., don’t match anymore)).
It all depends, and everything flows. 
