However, I wanted to commend your reply. It seeks to educate without judgement. Cheers.
I think if we were closer to ideal science, we'd work harder to verify numbers as a first step. More replication means stronger foundations and less wasted work.
There will always be some bad results that stick around for a long time before being overturned. But the median lifetime of bad results can change based on how we prioritize research. That statistic might currently be far from optimal.
The problem is, and has always been, that these alternative theories are never as accurate or precise as GR and their observational evidence is never as good as what we have for DM and DE.
It's not a conspiracy that scientific consensus is that they both exists, and no one is preventing research into alternatives being done. Significantly more money goes into research that accepts their existence, yes, but that's because most scientists do as well. What outcome do you want? To force scientists to work on theories they don't put any stock in? There is still plenty of interest in research papers written by people advancing alternate theories. Good ones are widely read by the entirety of the community, but you make it sound like the scientific community is actively suppressing anyone from researching anything that casts doubt on the existence of dark energy and dark matter, and that's just not true.