I've had the complete opposite experience (I replaced their Pop OS with Arch Linux). With light usage I get about 10 hours, if I'm playing games or something then yeah it drops a bit but not that much. It easily lasts the duration of an intercontinental plane flight which is my primary use-case.
Maybe it's because I don't actually use it all that much, so my battery hasn't had many cycles put on it. I only use my laptop for travel, normally I have a desktop. That's why I went for a small, highly portable model.
My experience is the same. I replaced Pop with Arch running a pretty low-resource desktop setup (i3 and generally lightweight programs) and I can get roughly 10 hours with very heavy usage: Firefox with a handful of windows/dozens and dozens of tabs open, Docker, Spotify, etc.
Not terribly impressive compared to something like the newer Apple silicon MacBooks but also not terribly offensive considering I don't often work far from an available power source for super long stretches.
Maybe it's because I don't actually use it all that much, so my battery hasn't had many cycles put on it. I only use my laptop for travel, normally I have a desktop. That's why I went for a small, highly portable model.