I believe the mistake they are making is assuming that objects as large as stars all explode with the same luminosity. Or maybe it's just deliberate - trying to see how far they can BS and keep the research dollars flowing? It's worked for decades I suppose. You could call it their business model! Another mistake is probably assuming that individual variable stars have the same metallicity as their host galaxies. It's just not believable. They can show me all the math in the world, and I just won't accept it, because it's stupid. It's garbage in, garbage out (GIGO). Their data is garbage. Their theory is based on the data, so their theory is also garbage.

The only method that I accept as unassailable is triangulation of distances, also known as the "parallax method". They need resolution several orders of magnitude better to triangulate the distances to the most distant objects in the universe. They are going to have to do it eventually, so they might as well get to it. And they should stop wasting time on "shortcuts" that don't work, and that give results whose error bars don't even overlap.

I would someday like to read about how the universe actually is, and know that what I am reading is a fact, indisputable and readily understood by any grade school student.