The more I dig into quantum computing theory, the more it looks like one big fat hyped hoax of 2000s to me. It's not a computer per se, but more like a measurement device for certain quantum states of a predefined circuit, an 'analog computer' with noise levels and margins that never gives any accurate readable/recordable result, and where any next reading will differ.
Yes, it still may act like computation device for specifically designed tasks, but overall it's more of a machine to read states of certain predefined circuits. Like your typical light bulb and thermometer can as well act as a 'computer' for voltage/current-to-thermal conversion where you 'compute' (measure) how much thermal comes out from the light bulb at certain voltage/current with a thermometer.
The biggest issue of this all, as already stated above, is that it gives analog output which is TOO noisy to be used as valid computational result to rely on, except for the very specific cases where you are fine with noisy output and don't need the 100% exact result. If accuracy matters (like with any integer to integer computation), it's not the task for this kind of 'computing' device.
So indeed chemistry where measured particle state is always 'undefined' and changes rapidly may be the good (if not the best and only) viable application for this quantum type of thing. Mechanics (especially engineering mechanics) would probably already be tough for Q'C's because even if particles involved in the 'computing' (measurement) process still act mechanical, with some assumptions and divergencies, precision does actually matter here, and getting stochastic data is not actually tolerable.
Mechanics simulations, like material endurance simulations, can be a task though because the final product acts in a noisy world with lot of interactions. But it's not a computation per se again, it's more of a widely spread stochastic parameter testing and measurements.