Complex sentence: Quantum computing might allow certain problems, that require an exponential amount of calculations, to become feasible, but it has practical and theoretical challenges that may never be overcome, such as the mass production of qubits, the fundamental building block of quantum computing.
Split into simpler sentences: Quantum computing might allow certain problems that require an exponential amount of calculations to become feasible. However, it has practical and theoretical challenges that may never be overcome, such as the mass production of qubits, the fundamental building block of quantum computing.