Try approaching it not as "let's change everything," but as "let's make things easier for ourselves." For example, you could suggest a pilot project for one department or one type of documents - that way the risk is minimal and management will be more willing to agree. The key is to show concrete results: less time searching for files, easier version recovery, faster access to what people need. If your company has older employees, pick a service with the simplest interface possible (Google Drive is usually simpler than complex systems) and offer to run a short training session. And also - clarify whether there might be specific reasons they're not using cloud storage: security requirements, company local servers, contracts with clients. If you approach it with an understanding of "why things are this way now," it'll be easier to negotiate the transition.