Microsoft 365 Business Basic is aimed at companies that primarily want to work cost-effectively and do not have high demands on Microsoft’s internal security, because the necessary security measures are established through other means. Microsoft Basic includes: web- and mobile-based Office apps (Word, Excel, PowerPoint, Outlook), business email with Exchange, Teams collaboration, SharePoint, and 1 TB OneDrive storage – no installable desktop apps or advanced administration/security. This may be sufficient for your needs. From experience, this may be suitable for some of your users while others rely on different plans. That is also possible.
Microsoft 365 Business Standard
Microsoft 365 Business Premium includes everything from Standard plus advanced security and device management features (e.g. Microsoft Defender, Intune, identity/access management). This allows organizations to better protect data and centrally manage endpoints. Premium is the right choice when protection, compliance, and management beyond standard productivity tools are a priority. Such organizations include:

• Companies with multiple locations and mobile employees

When devices and data are used outside a central network, Premium enhances security through centrally managed device and app management (Intune), MFA, and protection against data leakage.

• Public-law organizations

Government agencies, municipalities, educational institutions, or public-law entities (AöR) often have high compliance, archiving, and security requirements. For these, Premium is generally the more suitable option due to its advanced protection and governance features.

• Companies with high requirements for identity and access control

When Multi-Factor Authentication (MFA), conditional access, Single Sign-On (SSO), and protection against compromised credentials are important, M365 Premium offers clear advantages.