Why are wormholes unstable?

Could you please elaborate on the instability of wormholes? Could it be due to the extreme curvature of spacetime caused by their existence? Or does it stem from quantum fluctuations within the wormhole throat? Could the instability also be linked to the violation of energy conservation laws that wormholes are hypothesized to permit? And finally, how does this instability affect our theoretical understanding and potential practical applications of wormholes in physics?