[airbreather]

The conversion of kinetic to potential and back to kinetic energy is a form of energy storage, but not creation.

Harnessing gravity could occur in the form of the "slingshot" orbits, where a spacecraft steals a small amount of the stored orbital energy of the moon or planet from it's parent plant or sun, but due to the relative masses and speeds the impact is real, but practically negligible - steal too much energy from the orbiting body and and there will be a noticeable impact to the orbit.

[aspiretoreality]

Hmm... for example, the scheme of solar or tidal energy to move water uphill, then grab hydroelectricity? is an example of storing gravity? is that a valid characterization?

And yes, you immediately got the worry; that accessing gravity would at scale over a few hundred years, be a danger.

[airbreather]

In the uphill concept, consider gravity as the spring or rubber band that is stretched.