FWIW, I had a Dell laptop that I put Ubuntu 22.04 on when I got it, and the battery life was atrocious; closing everything except Firefox, closing every FF tab but one, stopping background services, setting the screen to half brightness, I got about an hour and a half of battery life.

Went and installed Slimbook Battery and left it at default settings and got several more hours of battery life without having to close everything. Had to reinstall later and just installed TLP and left it at default settings and still getting far better battery life.

Not sure why Ubuntu is so cripplingly bad out of the box when it's so easy to fix, but if you haven't tried that it might be worth checking out.