Wilder built it specifically to address the problem that any single lookback-period produces false divergences. By combining short, medium and long windows with decreasing weights, the indicator is less sensitive to the arbitrary choice of one period.
That design goal is genuinely thoughtful and is the reason it is worth knowing even though it is less popular than rsi, which Wilder also created.
It is not a cure. Blending three lookbacks averages away some noise but also blurs turning points, and the indicator still saturates in strong trends. The lesson worth taking from it is the general one: results that depend heavily on a single parameter choice should be distrusted.
Related: rsi, lookback-period, oscillator, divergence, momentum-indicator