Rather than forms being "created by" a user, they should be "owned" by the creator, with the ability to assign ownership to someone else.
If a form owner leaves the organization, the only way to change "ownership" so to speak, is to duplicate the already existing form (if that permission has been selected) so you become the "creator" and then modify it.
Workspace admins should also have permission to change ownership of a form, even if they do not own it.
If a form owner leaves the organization, it should be auto assigned to a workspace admin.
There should also be more options for giving specific users access to a form (similar to adding users to a project).