Office productivity covers word processing, spreadsheets, presentations, email and calendar, file storage and the collaboration layers around them, often sold as a single suite. Almost every employee uses these tools daily, and they are where most of an organisation's documents, correspondence and working knowledge are created.
The sovereignty issue is the depth of integration. A suite such as Microsoft 365 or Google Workspace combines identity, storage, mail, chat and AI assistants, so a decision on one component pulls the others along. Document formats, macros, add-ins and shared-mailbox habits tie users to one ecosystem, and administration, logging and key management run through the vendor's cloud. Where an AI assistant reads your documents to answer questions, check where that processing takes place and which content it can reach.
For a European option, look for support for open document standards, real-time collaboration in the browser, mail and calendar compatibility with common protocols, options for customer-managed keys or self-hosting, and a realistic migration path for existing files. Consider a gradual approach in which one function moves first, such as file sharing or the editor, instead of replacing the whole suite at once.