Local Folders is a placeholder in case you create local folders, nothing more. From the copies&folders pane, you can put archives wherever you wish.

That's the thing : I didn't want to create local folders. Maybe I did I, I don't know. In my IMAP accounts, when I hit Archive for a given email, it goes in the Archive folder under "Local folders".

But now I just found out that I can configure the archive destination under "Account settings / Keep messages archives in : ", so I can have each account have their own Archive folder like I was used too with the other email client starting with O (sorry for even mentioning it).

That said, there is not much use of the "Local folders". If it can be removed, i'm all ears.

I was glad to assist. Thunderbird has many options and it takes time to learn them all. No, Local Folders can't be removed. :)

By the way, consider using Local Folders. I find them to be indispensable. For example, suppose you discontinue an email address (or it gets taken away) and online access disappears. You can copy all messages from that gone-by account to Local Folders for archive and searching purposes. Or, if your email provider has quota limits, you can move the oldest ones to a local folder and free up space.

And back up your Thunderbird Profile regularly!

Maybe you're one of the many people who don't use and value old email like I do. For me, they are a searchable record of the past several decades of my on-line and "real" life.

I do. Thanks for your insight.