At the moment you have to click into each customer, but on the Public Roadmap there is a new item for Microsoft 365: Tenant Health Dashboard which states it will have Backup Gaps and Backup Health for all the Tenants on 1 screen. Full description is as follows:
Give your techs a more complete Microsoft 365 security picture than they’d get in the Microsoft Admin Center. Catch auth failures, backup gaps, and compliance drift, alongside backup health and baseline compliance scores Microsoft doesn’t expose, across every tenant, in one screen.