Throughout "Black Adam," fans learn a few things about the Helmet of Fate that gives Dr. Fate his abilities and powers. One: it's "alien." Two: only the worthy can even touch it, as noted in a conversation aboard the Justice Society's airship. Lastly, putting it on exacts a toll on the wearer, which gets exhausting. In fact, what happens when the helmet 'turns on' is that the wearer is "possessed," as Dr. Fate explains.
This helmet has a long history in DC Comics lore. Although the movie seems to be taking from that lore, it's not staying completely accurate. According to the fan-based wiki based on the comics, for example, the helmet is not an alien object but an ancient one created by the Lords of Order, who were present at the dawn of humanity. It is truly a coveted object, turning its wearer into one of the most powerful superheroes in DC canon. And, as pointed out in the film, it has some choice regarding who can wear it and when.
In the movie, the helmet's powers include the ability to see into the future and to project multiple images of oneself, telekinesis, and invulnerability, which are just a tiny fraction of the powers the helmet bestows wearers in the comics. Those abilities, in different DC properties, have also included manipulating natural elements like fire, air, water, and earth. In DC canon, the helmet comes along with two other items: the Amulet of Anubis and the Cloak of Destiny, which also grant additional powers.
