It’s kind of sad that even after 15+ years, no one has caught up to Dropbox. None of the other cloud providers do proper block-level sync, and I hear much less about Dropbox breakage than other providers.
It does make sense because OneDrive, iCloud and Google Drive are tie-in services. If you use Microsoft 365 / Apple / Android you are “forced” to use them to gain access to certain features, meaning there is no competitive pressure.