The ones in the image of the post are all old, rehashes from classic episodes.

When the Borg first appeared towards the end of TNG season one, all we saw was destroyed colonies. It was a mystery who or what was causing this.

Or, consider how we heard about the Romulans before first seeing them in TOS.

A slow revelation of a new and unexpected opponent, very different from the ones we’ve seen before, would be much more interesting than revisiting old ones repeatedly.