I followed the link offered by Jomel and all I can say is that this is one of the main sources of dissatisfaction towards Office at this point in time.
The logic behind it makes some sense from an architecture point of view but it brings with it more cons than pros. It strains to much the OS, works poorly with non SSD drives and whenever you have someone with a more dense and complex folder structure in
Onedrive.
For people not using Onedrive yet this is a requiremet if you need to use colaboration tools but a pain has the thresholds are not set properly.
From a user point of view this should be seemless, weightless and on demand. Rather than forced upon you.
it is also distasteful the arrogant lack of interest from Microsoft regarding this high impact issue (if you don't believe me just google it).
Collaboration wise the cache needs to be on the server side not the client. I face on a daily basis countless episodes where this solution causes problems with shared files forcing users to colaborate the old fashioned way (creating new files) to be able
to work (and i am just referring to people and server in the same network).
Sadly I see the same issue at home has a O365 user. There i am growing even more displeased both with Office uploader and Onedrive file management.
I am starting to see my O365 investment as a costly mistake and currently considering my options.