>>715146442shamus young once wrote an article about how and why his articles got way longer over the years and he said it's mostly got to do with addressing the most common arguments people will have in a satisfactory way, so you need to state your opinion, why you think that way and give an example (or multiple to be safe) and then rebutt the most common arguments people might have. that's fair enough i think, and especially with a big or unique game and making solidly built arguments i can see why a youtube review might be the length of a damn movie
although i think some youtubers milk it because good god, im not watching a 12 hour review on the witcher series or a 40 hour video on persona 4. i watched hhomber's 3 hour deus ex video at 2x speed and still got everything out of it.