As far as I know from my real experience.
It takes a lot of time to rank a highly competitive gig. You may have to spend a lot of time to get orders. If your gig comes to the first page, you have to complete many tasks.
If you work with a low competitive gig, your gig will rank on the first page in a short time. If you can seo the gig properly and deliver for the first time some order time.
I would advise you as a new seller to publish low competitive gig.
Thank you