Yes OneDrive is such a cluster. A lot of resellers will try to sell SharePoint as a drop in replacement to AD/SMB shares and it’s not and it causes all sorts of issues if you try to use it that way. We get all the same problems with OneDrive creating endless shortcuts if you use more than 1 PC, problems with the sync client creating new folders for automatically synced libraries every time it has a major update and so on.

If you (not talking about you specifically) half-ass the migration to 365 instead of completely retraining your employees on how to work with files and how to use SharePoint correctly. The problems is that the marketing and documentation make it seem easier than it is, and so most orgs don’t realize it until it’s already become a shitshow. That’s how it was for us too.

365 increase your risk profile as it increases the dependency on an outside vendor and increase the attack surface, but it gives you so much more tools for mitigating the inherent risk in running exchange, SharePoint, RDP on premise that it’s absolutely worth the investment. If not 365, then workspace. In my opinion you will spend more trying to maintain and properly protect AD+Exchange than you would properly configuring M365, Entra (Azure AD), and Intune.