Dropbox makes it almost impossible to retrieve your uploaded files, especially if they are large. It is as if they are deliberately holding your data hostage, so you don't drop them. That seems to be their business model.
They don't tell you the size of your all your folders (only each on individually, one at a time)nso it is practically impossible to organize your folders by size to see which can be removed from the cloud.
You cannot even do something as simple and basic as print out a list of the folders and files you have uploaded.
When you unsync a file that is only online it does not download the data again back to your computer. Only the list of folders and files becomes visible in your computer, but the data still stays online.
They put unrealistically small limits on how much you can download, even with a paid plan.
Their whole approach is unintuitive and confusing.