How do you charge your clients? Based on your description I think you’re not charging hourly rate so once the order is ready, deliver it. Fiverr is a business, the sooner you finish the sooner you can start on a next order.
For example, I don’t have an hourly rate on my website redesign gigs. I deliver them when they are ready.
My clients pay for my knowledge, experience and value I add to their business, not for the time I spend on their website.
Regarding, more time = hardworking, I agree with @raff_el
If a buyer gives you a poor review due to fast delivery then either you’re dealing with a difficult buyer or you did a shi**y job explaining your service.
PS. @umerkhawer looking at your gigs I would be more worried about the license. If you’re using templates from videohive then make sure you actually have a license for each sale.
Let me give you an example.
This is your gig https://www.fiverr.com/umerkhawer/make-kinetic-touch-promo-video
This is the template from videohive https://videohive.net/item/touch-typography/16687984
The regular license is $37 and the extended is $110 and yet you’re charging $20 for the basic gig.
Either you’re doing charity work or you’re selling videos without license which means you’ll be reported and possibly banned.
Get it sorted first and then worry about the minutes you spend on each project.