Fiverr is not an employer who seeks ways to retain sellers. If anything fiverr would like bad sellers to leave.
In the first years on fiverr it was a different story. Fiverr actively interacted with sellers and found ways to actively assist them in many ways that have since been abandoned, as the number of newer sellers has expanded exponentially.
Now there is a glut of sellers in all categories and fiverr has shifted its focus away from helping and encouraging individual sellers, to finding ways to promote the best sellers while discouraging the bad ones.
The ways that sellers are encouraged to stay are the benefits built into the site itself, such as having a platform that handles all aspects of self employment, website technology and support, advertising, payment processing, and marketing.
Fiverr does not offer employment benefits like insurance to sellers to keep them.
It has no need to try to hang onto sellers in this way like a traditional brick and mortar company.