OneDrive _for business_ is built on Sharepoint. Onedrive ... erm ... not for business (?) is an entirely separate product, and they don't interoperate.
Which is another baffling decision by Microsoft branding, since for regular users they make no distinction. It only becomes apparent when you discover you can't work with people outside the organisation.
That is oh so weirdly common in MS ecosystem... like Skype for business being Lync and being significantly worse than "just" Skype (no idea what MS teams voice chat is based tho)
You can share externally with Onedrive for business...
It's a setting in Sharepoint admin...
Once again, people here have no idea that most of their complaints with O365 is how management sets the security policy... not the platform itself...
https://learn.microsoft.com/en-us/sharepoint/turn-external-s... :)
You are right in that it used to be bad.
Groove.exe... The old Onedrive for business client was a horror
Yes, but not (simply) with OneDrive, as the branding would suggest. Lesson learned, anyway.