The nature of black holes is still an active area of research, and there are various theories and hypotheses regarding their behavior. However, based on our current understanding, black holes do not typically serve as portals to other dimensions or universes.
Black holes are extremely dense objects formed from the gravitational collapse of massive stars. Their gravitational pull is so strong that nothing, including matter and light, can escape their gravitational grasp once it passes the event horizon—the point of no return. Anything that crosses the event horizon is thought to be trapped within the black hole, leading to a region of spacetime with a gravitational singularity at its center.
While some speculative theories, such as certain versions of string theory or brane cosmology, propose the existence of extra dimensions or parallel universes, there is no conclusive evidence to suggest that black holes function as gateways to these realms. Currently, such ideas remain largely speculative and are still the subject of ongoing scientific investigation and debate.
It's important to note that our understanding of black holes and the nature of the universe continues to evolve, and future discoveries could potentially shed new light on these topics.