Exactly. This myth keeps being perpetuated, for some reason.

I'm typing this from a ThinkPad X1 Carbon Gen 13 running Void Linux, and UPower is reporting 99% battery with ~15h left. I do have TLP installed and running, which is supposed to help. Realistically, I won't get around 15h with my usage patterns, but I do get around 10-12 hours. It's a new laptop with a fresh battery, so that plays a big role as well.

This might not be as good as the battery life on a Macbook, but it's pretty acceptable to me. The upcoming Intel chips also promise to be more power efficient, which should help even more.