I just think that Lemmy can’t survive if there is no way to make people aware that a particular post is OC to a fediverse-Plattform.
I have seriously no idea what you even mean by that. Care to elaborate why a site that managed to exist without an OC tag for nearly half a decade is suddenly doomed if there’s no extra OC tag now? Or why good content can not be appreciated if it doesn’t have the right tags?