I am a advocate of alternative models and try to formulate such models just to see if I can. I also strongly believe that alternative models are needed just in case standard models fail. That said, the standard LCDM with a very simple cold non-interacting, except by gravity, dark matter fits most of the data and is very economical in terms of complexity.
Consider this alternative I worked on several years back, an action and lagrangian for the Lambda CDM model meant to explain how we can see solid evidence for it at the cosmological scale but can't detect it in Earthbound experiments.
It is complicated by the addition of massive scalar and vector fields which are functions of the curvature of space-time R, a variant of so called "f(R) gravity". So far everything it predicted has been shown to be true YET as predicted we have not found any WIMP's yet. It should be known that I am formulating a similar but not identical model using the theoretical framework I have written of here recently, unification by relativization.
Compare that to the standard Lambda CDM lagrangian which would go something like this.
It is much simpler and therefore much better until it contradicts data in a way that really truly cannot be explained by it.
So for the time being Occam's Razor favors the simple standard model over any and all alternatives. HOWEVER, In science nothing is ever truly final and further evidence can overturn any standard model. Thus any work that challenges the standard models is of great importance.