I don’t think there is any objective way to settle this debate. I think if you enjoy tuning skis, go for it. I like sharpening knives and tools so I get it. But I don’t bother with my skis.
Try it and see.. Note that when you race, you often do it on watered+salted hills where hundred people have followed the exact same track. Really icy.
It also might be a thing we're you're just not good enough to notice. I don't mean that as a slight, but seriously changing the angle of the edge of a ski is basically like racing a completely different pair. The feel of how it engages can quickly become too aggressive or lax.
If you gave a blind test, same exact skis but varied the tuning, most serious racers would be able to tell you what changed after a few turns. Edge or base bevel angles, wax, tuned or de-tuned. I haven't raced in years and I wager I would do pretty well on that test.
Youth racers tend to ski with one set of edges on the inside for training, and the other edges inside for racing (under the theory that the inside edges take more of a beating. Who knows if that is accurate). If you ever see youth racers on slalom skis (which are chiral, since they have tips that deflect ski gates), you’ll often notice that the skis are on the “wrong” foot.
Also, that's awesome that you competed WC moguls. I probably saw you compete depending on when you were active, and we almost definitely know some of the same people.