Plus, when it comes to data/file sync tools like Dropboox, we need interoperability with existing tools: File Managers, filesystems etc. Not GUIs. Electron et al. are good for cross-platform GUIs, not CLIs or daemons.
I only mention Electron as an option since they don't attempt to get anything working, also I would mostly use these services on my own desktop, on a laptop I rather download files I need via a website interface directly.
Plus, when it comes to data/file sync tools like Dropboox, we need interoperability with existing tools: File Managers, filesystems etc. Not GUIs. Electron et al. are good for cross-platform GUIs, not CLIs or daemons.