Admittedly, it is fairly ambiguous what the benefits of "being worthy" are. In Avenger: Age Of Ultron, <PERSON> says that if any of them (the other Avengers in the room) could lift <PERSON>, they would become ruler of Asgard. And in the original <PERSON> movie, as soon as <PERSON> becomes worthy (after preparing to sacrifice himself to save his friends on Earth), the hammer flies to him and all of his powers are restored. This implies that there was nobody else on Earth worthy enough to wield the power of <PERSON> at the time of <PERSON>'s exile. However, we see the Vision wield <PERSON>'s hammer (we're assuming he's worthy, and that he's not able to do this because of any other reasons), yet he does not instantly gain the power over thunder and a cool suit of armor like <PERSON> did in the original <PERSON> movie, nor does he become ruler of Asgard, like <PERSON> implied any wielder of the hammer would.
Ultimately, it comes down to the fact that <PERSON> is <PERSON>: the god of thunder's hammer. At least 3 (<PERSON>, <PERSON>, Hela)(possibly 4: <PERSON>) characters other than <PERSON> have the ability to lift the hammer, but none of them have gained <PERSON>'s powers from it. Even though we see in Thor: Ragnarok that <PERSON> wielded it before <PERSON>, <PERSON> gave the hammer to <PERSON> after <PERSON>'s fall. Thus, we can assume that the hammer's enchantment is largely focused on channeling the powers that the wielder already has, and the hammer itself carries no powers other than those granted by being forged for a king in the heart of a dying star, yada yada yada... 722
Perhaps, since the hammer was made for Asgardians, it can only be used in combination with powers from Asgard. For example, <PERSON>, the god of thunder, can focus his thunder powers through it, and <PERSON> probably focused whatever death powers she already possessed through it. But both <PERSON> and <PERSON> can use their powers apart from the hammer. It doesn't provide any of its own. <PERSON> can't shoot swords from his hands, and <PERSON> can't summon lightning from the sky.
This argument is supported by the entirety of Thor: Ragnarok, where the hammer is destroyed fairly early in the movie, yet <PERSON> still is able to use is powers. <PERSON> explains that <PERSON> could possibly (incorrectly) have been using the hammer as if it was carrying the power, but in reality, it was meant to be a means for <PERSON> to channel the power he already possessed.
That hammer was to help you control your power, to focus it. It was never your source of strength.
In short, <PERSON> is the only god of thunder. The fact that other's have lifted the hammer, but been unable to use it as more than just a hammer, shows that the true power (thunder and such) comes only from <PERSON>, or possibly whatever Asgardian is currently meant to wield it. 722