A counterexample is meiotic drive, where alleles disrupt the meiotic process in order to favour their own transmission, even if the alleles in question ultimately produce a less fit organism.
Whilst this is not an inherently positive observation, I think it does illustrate that the fatalistic picture you're painting here is incorrect. There's room for tentative optimism.
That is not correct. Darwin did make a mistake, but it was not the fundamental dynamics of the process, but that he chose the wrong unit of selection. Darwin thought that selection selected for individuals or species when in fact it selects for genes. Richard Dawkins is the person who figured this out, but Darwin knew nothing about genes (OoS was published only three years after Gregor Mendel's work) so he still gets the credit nothwithsanding this mistake.
Of course. Variation is the other part.
> gene flow or genetic drift
Those are two mechanisms by which variation occurs. This is not something Darwin got wrong, he just didn't have all the data. Genes were unknown in Darwin's time.
Clearly it isn't Darwinian selection, because it can favour transmission of genes which are not conducive to survival.
Clearly it isn't variation, because it tends to reduce the degree of genetic polymorphism within a population.
> it isn't Darwinian selection, because it can favour transmission of genes which are not conducive to survival
This is the one thing that Darwin got wrong: he thought that the unit of selection was the organism, but it's not. The unit of selection is the gene. Richard Dawkins is the one who figured this out. Meiotic drive is not Darinian selection, but it is selection. But Darwin could not possibly have known this because genes were unknown at the time.