In the first couple of years of WikiTree, GEDcom imports automatically added people. We ended up with tens of thousands of profiles that were duplicated, that had no dates or places, or missing names. People would import their data, and then never touch the profiles again.
That's fine in a personal tree. For a shared tree, duplicates and lack of sources and unattached profiles are a problem. We decided to make sure that for every profile a person adds to the shared tree, they check for dates, duplicates, and other critical information.
It's a bit more work up front, but it saves a LOT of work later. Ten years after changing the rules around gedcom imports, we still haven't finished cleaning up all the mess from the first few years.