It has become very clear to me in the last year or so that people are all different (who knew!!)
Some people don't suffer from hunger when they eat the standard western diet. These are the people who might be so busy at work they forget to eat. That always sounded completely unrealistic to me, I would NEVER forget to eat. In fact, during the day I would always be planning where to eat, and when visiting friends overnight I always took some supplies with me in case they didn't feed me enough. As a child I always had 'midnight Frosties' (supper, in other words, just before bed) as I was hungry.
I may have felt hungry but my body wasn't really hungry, but that isn't something you can do much about.
So for me, the miracle of my hunger pangs disappearing is what makes Keto so suitable for me. And the poster above is right, I doubt I am in ketosis now (eating too many carbs), but I am eating low carb enough that the hunger doesn't come back.
And yet for other people, who aren't hungry two hours after eating a big meal, this benefit of Keto eating choices means nothing.
The OP asks who benefits from Keto? I think one clear group are the 'labradors' like me who are always hungry. We are usually fat because we are eating when it isn't necessary, and even if we are eating the right things (I used to often snack on fruit), too much of that means too many calories and getting fat. People used to say that a bowl of porridge would fill you up till lunch - no chance for me, I was hungry again an hour later.
Other groups who might benefit are the epilepsy/headache/diabetes people, or people who need sustained energy all day without troughs and spikes. For those who need explosive power in their fitness plans then it's not going to be good for quite a while.
The upside of this way of eating for me is that the food we eat is very unprocessed - and we don't have to look for the Low Fat versions of everything in the supermarket. I have been a lifelong teetotaller so don't miss the beer which I think could be an issue for lots of people. I just drink water and tea (I have had to cut out the orange juice).
There is no harm in the Keto diet, it works really well for certain groups of people, and isn't necessary for others. Choose if you want to do it. But please DON'T tell me that the hunger/not hunger thing is in my head, as it certainly isn't. I and many other fat people who do Keto can show you that there really is a difference, and for us this is the key.