Issues copying the Dropbox folder to my external drive to back it up

I am on Dropbox Plus, I've installed the desktop app on the latest version of macOS. I do not use Smart Sync, as I want all of my files to be available locally on my machine, as well as online. I regularly do a manual copy/paste backup to an external drive. The folders I am copying are all marked with the green check on Finder, meaning they are available offline. 

To my surprise, during the last backup, I found out that copying the 'Dropbox' and 'Google Drive' folders from my user's root folder onto the external drive only created alias folders. This could have had some really nasty consequences: making a backup that was actually useless, because the actual files were not being copied! 

Thankfully I realised something was wrong because the disk utility did show that the used volume on the external drive was much less than expected. What was also very confusing is that when looking at the folders size on Finder, the size of those alias folders was counted as identical to the size the original folders have, even if they are just aliases—this made me belive they did contain real data, but still the disk utility did not show any correspondent used disk space. 

This is extremely confusing! Finder does indeed give an indication that there are aliases, in fact there is a small arrow next to them, but it's very easy to skip them and not notice. From a user's perspective, my mental model is clear: if I want to create an alias, I must deliberately choose that option. If I copy a folder that sits locally on my drive iand paste it onto another drive, there is no reason on earth why Dropbox/MacOS should paste an alias, instead of the full folder. 

In order to make sure that the folders were copied properly, all I had to do was to re-create the 'Dropbox' and 'Google drive' destination folders in the external drive manually, then paste all contents into them. For some reason, this issue only happens when copying those root folders, not their contents. This is also a broken conceptual model that cannot in any way match with the mental model that users have. One way or the other, you can't create an alias or copy the actual folder, depending on what folder it is. 

I am hearing that these problems are due to the migration to macOS's File Provider. I don't know if that's the case, but this cannot happen. Dropbox must address this issue urgently. Don't mess with my data! My recommended solution is that if the user copies an alias folder, the app should ask whether the intention is to actually copy the original folder. I understand that the software is not doing anything wrong here from a logical perspective, but still, people can easily do the wrong thing, if the software doesn't go the extra mile to prevent accidental data loss.