Because it is entirely plausible that you need to add a folder where only you know the ID that another device has already chosen for it. Often you will get a sharing “invitation”, but otherwise you will need to enter the ID manually. Conceptionally, there is no difference between adding a “new” shared folder (with a new, unique ID) and “joining” a shared folder which has already got an ID from somewhere.
As mentioned, that feature didn’t always exist. But you might also want to configure a device before it’s connected to the outside world, if you’re in a cabin in the woods or going to ship it to a research station on Antarctica.
And once the folder is created, you can only change the ID with Actions/Avancé settings.
Even it would be cosmetic only, you can pick a friendly looking ID that tells about the folder purpose.
BTW devs, are there any limits (length/char set) for the folders ID ?
Great piece of soft isn’t it Wpg? Sun shine to you from 64.
To be able to enter the folder ID is a necessary feature of you want to connect two folders (perhaps very far from each other) where you have done an initial sync by other means (such as copying files from a USB stick):