There’re divergences between the MCU and comics regarding restrictions on the Infinity Stones.
Specifically, the restriction for humans not able to use it does not exists in Marvel Comics. The human character and villain The Hood manages to use 3 of them without any specific consequences over a sustained period of time.
While in Ryker's Island, Hood befriended an Inhuman named Ertzia and learns the location of one of the Infinity Gems. Once out Parker Robbins hires several people to take him to the former location of the Inhuman secret city, Attilan. After eliminating them, he locates the Reality Gem. Some time before, the six Illuminati locate the Gems and each member takes possession of one to make sure they would never again fall into the wrong hands. But Black Bolt is dead, and the royal family did not know about the gem he had hidden when they moved the Inhumans off of Earth, thus it was left unguarded. Using the Reality Gem, the Hood swiftly uses it to steal the Power Gem from Reed Richards. His quest next takes him into conflict with the Red Hulk and the Avengers. Hood later targets the other Illuminati members for the other Infinity Gems. At a later point in time, Robbins uses the Reality Gem to heal Madame Masque's face.
The Hood uses the red (Power) and yellow (Reality) gems to steal the purple (Space) gem from Iron Man,
So in comics the answer is a human can wield the 6 Gems. In the MCU given the shown events with just 1 Stone, it is very likely the human would be consumed before actually becoming omnipotent.
It’s not clear gathering the 6 Gems makes you omnipotent, more likely just very powerful. From Wikipedia (bold mine).
Thanos becomes nearly omnipotent, and challenges the Silver Surfer and Drax the Destroyer,
This is further indicated by the fact that The Living Tribunal is able to decree that the gems can’t be used in unison (which contradicts the being with all 6 being omnipotent).
This will later come in place when Captain America tries to use them and even though he destroyed another universe, the gems were scattered and destroyed (something that would simply not happen if you are omnipotent).
Captain America uses the Infinity Gauntlet to push the other universe back, but because of the decree that the Gems cannot be used in unison, the Gems shatter, except for the Time Gem which vanishes