So how long should somebody play then?
That's subjective but if someone played Fallout 1 for 2-3 hours and then went on to make several youtube videos reviewing it how much should you actually value their opinion? In the case of Fallout 76 the game isn't even a static entity, it's gone through several major iterations since release. If they aren't actively playing it and/or haven't played it in-depth then they should probably shut up about it. But it should be no surprise that their audience is primarily people who don't play the game because anybody playing the game isn't watching videos about how terrible it is.