It is best practice and highly recommended to enable Application Guard for Office. This feature is available on Windows 10 2004 (20H1) build 19041 or later.

Microsoft Defender Application Guard for Office (Application Guard for Office) helps prevent untrusted files from accessing trusted resources, keeping your enterprise safe from new and emerging attacks. This article walks admins through setting up devices for a preview of Application Guard for Office. It provides information about system requirements and installation steps to enable Application Guard for Office on a device.

Also Application Guard for Office is the official remediation for some 0-day attacks like CVE-2021-40444 (https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-40444).