Do we need soft cosmology?

We examine the possibility of "soft cosmology", namely small deviations from usual framework due to effective appearance soft-matter properties in Universe sectors. One effect such a case would be dark energy exhibit different equation-of-state parameter at large scales (which determine universe expansion) and intermediate sub-horizon clustering scale structure formation). Concerning soft matter, we show that it can effectively arise dark-energy clustering, even if is not soft. propose novel parametrization introducing "softness parameters" As see, although background evolution remains unaffected, extreme sensitivity significant effects on global slightly non-trivial softness improve behavior alleviate e.g. $f\sigma_8$ tension. Lastly, an extension cosmological perturbation theory detailed statistical mechanical analysis, order incorporate complexity estimate scale-dependent first principles, necessary provide robust argumentation favour cosmology.