Sharing actually is not a very helpful action, because when the dialog expands, the user has to select all the url, scroll horizontally to fetch the full url and after that, click Ctrl+C/Cmd+C to copy the link.
Simple Solution Proposed
Include a possibility for the user to select all and copy link for sharing document only with one click.
Context of full analysis and possible solutions:
One of the paths we would like to follow would be the possibility to immediately invite users&groups or send an invitation to cooperate for external users (by email), but this would require a bigger shift and further understanding about the permissions limitations and the conseuqences of giving the possibility to interact with permissions in more granular levels.