The phrase "much less complex" is correct and usable in written English.
You can use it to compare two things that are relatively similar, but one is simpler than the other. For example, "The new model of the phone is much less complex than the previous version."
The snails' farms are much less complex.
In this "RNA world," cells were much less complex.
I know that I am currently embracing a much more authentic and much less complex me.
The Swedish loans were much less complex than modern securitised assets.
The noble gases absorb and emit electromagnetic radiation in a much less complex way than do other substances.
Their internal silica skeletons are composed of a network of bars, and resemble those of radiolarians but are generally much less complex.
The proposed fixed-lag smoother is shown to be much less computationally complex than the existing fixed-lag Kalman smoother with infinite memory structure.
Third, we are reminded that the audit-focused social responsibility model that most companies have adopted is inadequate even for addressing the highly visible and relatively cut-and-dried issues of health and safety, much less the complex and hidden causes of modern-day slavery.
The exact mechanisms by which human IgG, much less antigen complexed to antibody, passes through fetal endothelial cells remain unknown.
While hydroxy groups at the benzene nucleus in meta and para position, i.e. resorcinol and hydroquinone (or their functional derivatives) usually result in equally stable iron complexes, they yield much less stable iron complexes than catechol (ortho) compounds.
They are low-crowned, large, and strongly rooted, with as many as four prominent ridges separated by deep troughs; the teeth are much smaller and less complex, however, than those in the true elephants.
