How to speed up iCloud Drive sync after migrating from Dropbox?

Migrated cloud services from DropBox to iCloud this weekend, hoping it would be as simple as copy+paste. iCloud is extremely slow to sync files (I check all the boxes: space, bandwith), I don't seem to fina any good news online. Seriously thinking in going back, even DropBox being more expensive.

[Re-Titled by Moderator]

Original Title: iCloud drive too slow