On the other hand, having as many users as possible use any password manager at all is an immense challenge as-is. It really doesn't matter what gets them using one as long as they do. If an OS-native one happens to have the lowest friction, so be it.
For everyone else, sure, there might be 100 people in the world that will actually audit their open source password managers. But that isn't exactly moving the rest of the industry forward (be it from the engineering perspective or the user perspective).
In this case, (almost) perfect is the enemy of good.