Aaaand.... Just found the answer: Eager loading.

I will just leave this here so if someone is searching for this answer via the same search terms as me, they might be able to find it!

Solution:

$videos = Video::where("videoUserID",$userID)
        ->with('videoAsset')
        ->with('thumbnailAsset')
        ->limit($this->limit)
        ->offset($this->offset)
        ->orderBy("created_at", "desc")
        ->get();

Alternate Solution:

$videos = Video::where("videoUserID",$userID)
        ->with('videoAsset','thumbnailAsset')
        ->limit($this->limit)
        ->offset($this->offset)
        ->orderBy("videoYouTubePublishedAt", "desc")
        ->get();