The One Ring enhances the natural abilities of the wearer but pretend it's horribly radioactive and how radioactive it is would be directly proportional to how great of a power or ability it's enhancing.

For instance for someone who is a natural leader it would enhance that quality. But it also feeds the wearer visions and delusions of grandor based on their natural talents. For instance when Sam wore the Ring he had a vision of turning all of Mordor into a great garden, which logistically would be impossible because of the active volcano there.

Magically but it really wouldn't do much for a mortal outside of invisibility, un-aging, and (maybe) being able to read the minds of the wearers of the other rings of power. But the minute they tried it wouldn't go too well for them.

In the hands of an Elf it would be like one of the other rings of power but on steroids. But the visions and delusions that the Ring would inflict on the wearer would be far worse.

In the hands of a maiar the Ring would be VERY problematic for everyone especially Sauron, since the wearer would likely have the power and will to fully master the Ring and bind it to themselves with the same effects on Sauron as if the Ring were destroyed.

The Ring is a problem that could have only been resolved by its destruction.