No. Thickness by itself is not a reliable measure of underlay quality or suitability. A better comparison looks at density, resilience, construction, intended traffic level, the carpet manufacturer's requirements, acoustic and thermal performance, relevant testing and the way the underlay behaves under load. A very soft or thick product can feel impressive in a sample but may not be the right support for every carpet, staircase or commercial application. The underlay should be selected as part of the complete flooring system rather than as a separate comfort upgrade.
