Because he's a striker - strikers score goals.
And he's not *that* involved like, let's not pretend he's turbo-Giroud. https://understat.com/player/5555
Look at the missed shots. That's not normal - we're creating chances for him, and despite the fact he's surpassing his xG rating, he's still not doing well enough with these chances. Some of those can lead to wins. I think it's basically what people want (or at least what I want) from him.
Stats tell a very small part of the story
Eye test > stats