Well, I agree with the analysis you laid out and I'll gladly admit, it subjectively seems "good" enough for me as it is without explicitly referring to either dialectics in general or specifically dialectical materialism (which is not as broad and difficult as dialectics in general, which I don't claim to be necessary).

However what does "good" or "better" mean exactly? We know it's a good analysis, because it's compatible with the principles of historical materialism. It looks at classes, it takes into account that society has to reproduce itself, it conceives of the world as ever changing rather than static and most of all, aims to change it in the right direction. So why is historical materialism good for producing analysis that is able to change the world? You can't say it's good because it produces good analysis, that would be circular. Why can we rely on historical materialism to produce good analysis? Maybe another method would provide even "better" ones? How did it's inventors arrive at it? By applying the more general philosophy of dialectical materialism to human history.

Why simple things like: "actual change in the world matters more than ideas about it", "contradictions drive the development of things", "things are defined by opposing principles", "gradual change turns into real difference suddenly" are true, is explained by dialectical materialism and that's what historical materialism is build on.

We don't all have to get into it, it's enough if some intellectuals keep it alive. But where it is forgotten completely, mistakes are made. A good example of a wrong analysis, that claims a vulgar materialism but lacks dialectics is the gender essentialism of terfs.