Fallout 3 has Wanderers Edition, a mod compensating for the absence of a hardcore mode in the game. This mod brings a lot of changes to the gameplay and increases its complexity. Thus, in Wanderers Edition you need to eat and drink, but the amount of supplies and ammunition scattered around the world is extremely limited, which significantly complicates the gameplay. This mod also extends the content of the game at the expense of the new armor, medicines, and various weapons, including guns from the first games of the series.
Taking into account that these days, even games with hard modes aren’t actually that hard, it looks like Fallout 4 will definitely need a hardcore mode designed by the mod community.