Many of us doing double work in order to call the Lightning Web Component in custom quick action. We have to call LWC in Lightning Component in order to show the LWC UI in quick action. Now Spring 21 brought way to call the Lightning Web Component from Custom Quick Action but it is not generally available (Pilot).
Note: This change applies to Lightning Experience desktop in Group, Essentials, Professional, Enterprise, Performance, Unlimited, and Developer editions.
Spring 21 Release Note: https://help.salesforce.com/articleView?id=release-notes.rn_lwc_action.htm&type=5&release=230