It all depends on what you want from gaming. Fortnite gives you a pure adrenaline rush, and quick success for one good action. And the blast of being lucky.

Minecraft gives you phases of meditative and relaxing actions like mining, logical problems to solve and feel the succes of, proudness about building something beautiful, adrenaline spikes in sticky situations, the happines of having a good idea, the endorphine rush of finding your first diamonds, etc.

It gives you more different kinds of reasons to be playing at the "cost" of a slower pace which isn't inherently bad either.

The reason MC is widely consudered better comes from the imense spread of player types.

Almost everyone has reasons to like it, even without the many ways to customize and modify the experience.