Ultimately, the end-state goal with automated shifting is increasing efficiency. The effect of that is generally either increased performance, or decreased effort. Said differently, the system can ensure that you’re pedaling at the most optimum cadence, helping you to avoid situations where you’re out of optimum because you’re too tired/lazy/distracted/whatever to shift the bike to a more appropriate gear. As a result of that, they’re finding with some elite athletes that they’re getting increases in wattage due to increases in efficiency.
The second subset of use cases and goals is really aimed at assisting an athlete with pacing, be it in a race or training. Today, bike computers (such as a Garmin) can easily tell you if you’re above/below your target, be it a wattage target or a heart rate target. But ultimately those bike computers will only beep/chirp at you so much – it’s up to you to do something about it and adjust intensity/gears to maintain plan.
With automated shifting – it’ll just do that for you. And on a bike, it’s shifting that controls effort. Thus you can simply set a race plan with a specific wattage target – such as 315w, and the bike will shift automatically to maintain that wattage. Similarly, it can do the same for heart rate or cadence. But let’s not get too far ahead of ourselves with respect to functionality.