Hot take: most people pack their sleeping bag wrong and blame the bag
I kept reading reviews saying bags were cold at 30 degrees, so I almost dropped $200 on a new one. Then a guy at the REI in Denver showed me that stuffing my bag loose into the sack instead of rolling it tight keeps the loft from getting crushed over time. Mine is a 5 year old synthetic bag and it felt ten degrees warmer on my last trip near Estes Park just from that one change. How many of you store your bag compressed in the stuff sack at home, because I did that for years and I'm pretty sure that was the real problem.