Python doesn’t have to. Windows supports both out of the box. Has been for many, many years

My (self-hosted) cloud storage is larger than the disk drive on my laptop. On demand sync is important to me. I really, really hope Linux will catch up to Windows in that regard.

Currently we have an experimental VFS feature on all platforms that is using some suffix appended to files when they are virtual empty placeholders. https://github.com/nextcloud/desktop/issues/3668

Yeah, no thanks. It’s a very hacky work-around and breaks the moment you use an application that tries to access the files directly.

OS-level support for cloud storage. OneDrive, Dropbox and all the others work seamlessly on Windows through the Windows API. You can browse all the files on the file system and once you access them, the OS will call back the cloud provider to download them. It works through all applications, all cloud providers. I am aware that some tools on Linux have something similar to work around the issue in user land. Some solutions are less worse than others but none of them are as good as on Windows.