From my limited understanding, a quantum computer performs computations over probability distributions, rather than over numerical values. Performing precise computations over probability distributions is a serious problem in many domains - physical simulations are just one. Another example is that could allow much more efficient and precise data fusion, and as a result - a leap in AI abilities, across domains where AI is used.
Unfortunately, even though a quantum computer "manipulates wavefunctions", you can still only measure the outcome once. The magic has to happen somewhere in between state preparation and measurement. It's more like a computer with an inbuilt RNG - but if you can reach the same result via multiple execution paths, the probabilities don't just add, but they can interfere like in-phase/out-of-phase oscillatins.
