Here’s a hint. When they have to insert not one but TWO placeholders to try to explain away observations that do not match the theoretical models (Dark Matter and Dark Energy), it means they don’t understand things very well.
I have a radical new theory. Maybe Dark Matter and Dark Energy don’t exist. We just haven’t figured it all out WRT the laws of physics. If your theory is correct, it doesn’t get holes punched in it constantly. This marks failure/lack of understanding #3.
My theory doesn’t require Dark Matter, Dark Energy or Dark Chocolate...........