For purposes like graphic design or color grading it's usually more useful to first focus on lightness contrast, then pick hue and chroma afterward. Having uniform steps of ΔE is not really important, and using that as a primary criterion will usually make for worse choices. Color is multidimensional and trying to simplify it to a single distance function is substantially misleading for this context.
The main purpose of ΔE is specifying error tolerances for specified colors / measuring small differences between nearby colors, so that e.g. if you hire someone to paint a car or print a magazine you can check that their output matches expectation sufficiently. For colors that are significantly different ΔE isn't that helpful a practical tool.
The main purpose of ΔE is specifying error tolerances for specified colors / measuring small differences between nearby colors, so that e.g. if you hire someone to paint a car or print a magazine you can check that their output matches expectation sufficiently. For colors that are significantly different ΔE isn't that helpful a practical tool.