The current version of lerna doesn't use useWorkspaces anymore, defaulting to using the workspace config if one exists:
ECONFIGWORKSPACES The "useWorkspaces" option has been removed. By default lerna will resolve your packages using your package manager's workspaces configuration. Alternatively, you can manually provide a list of package globs to be used instead via the "packages" option in lerna.json.
The current version of lerna doesn't use useWorkspaces anymore, defaulting to using the workspace config if one exists: