Muscle soreness is not necessary for hypertrophy, but often enough (but not always) it is a good measure of the effort/volume/weight/technique (so a proxy for the mechanical tension, the thing that we want, but it hard to measure directly).
id say, never being sore at all is maybe a sign you dont do enough for optimum results, but frequently being sore means the load is too high. And for health outcomes it probably matters less.