Why is geothermal energy considered a renewable resource?

There are several ways to extract geothermal energy, which is defined as energy that is extracted from the Earth's crust (geo meaning Earth, and thermal meaning heat).

The website RenewableEnergyWorld.com/Technical/geothermal-energy/

What constitutes a renewable resource is:

(I'm not sure I agree with that part of their definition; it takes years to replace a forest that can be harvested in a matter of days.) The link below also adds that the replacement period must be equal to or less than the time it took to harvest the resource in the first place.

Certain resources, like solar energy, are considered "self-replenishing" because they never run out and don't require human effort to replenish, whereas other resources need human effort to replenish, like planting trees to reforest a forest that has been cleared for wood.

The website investopedia provides a term or resource that is renewable.

Heat from the Earth is thought to be self-replenishing and thus renewable because it has an endless supply and doesn't require any work to replenish.

Geothermal energy is considered a renewable resource because it is derived from heat stored beneath the Earth's surface, primarily in the form of hot water and steam. This heat originates from the Earth's core, which continuously generates thermal energy through radioactive decay. As long as this heat source remains active, geothermal energy will be replenished over time, making it renewable. Additionally, geothermal power plants can utilize technologies to efficiently harness this heat without depleting the resource.