When syncing a OneDrive business account, the root folder name consists of "OneDrive" followed by the company name as registered in M365, e.g. "OneDrive - My Company Ltd.". For certain companies with longer names, this could result in lengthy folder names. There is a way to change (rename) this folder, though.

1. Completely quit the OneDrive application.
2. Using either Finder or Terminal, navigate to the folder: ~/Library/Containers/com.microsoft.OneDrive-mac/Data/Library/Application Support/OneDrive/settings/Business1/
3. There are a few INI-files in there. One will be a randomized SID-like number, followed by .ini, e.g. a183b583-a64a-28fd-818a-b4918a569c95.ini. Open this file with a plain text editor.
4. Look for a long line which starts with libraryScope =. In that long line is a reference to the root path (between quotes), e.g. "/Users/user/OneDrive - My Company Ltd.". Change this path to match the new folder name (and location if you want to move it somewhere else). Don't change anything else!
5. Rename/change/move the root folder name to match what you've specified in the INI-file.
6. Start the OneDrive application again.