There are various tools to optimize battery life on linux, most prominently:

• laptop-mode-tools (https://github.com/rickysarraf/laptop-mode-tools)
• TLP (https://linrunner.de/tlp/index.html)
• auto-cpufreq (https://github.com/AdnanHodzic/auto-cpufreq)

But at the end of the day it depends on various factors, so it will be a tinkering process.

I switched to Linux, because my very first confrontation to buy a Windows license myself weirded me out. It was quite casual. My exposure to Linux came from a few software development related videos. The workflows I saw looked much more efficient and fulfilling. To be honest, with a dying laptop running on Windows 8.1 I had an extra terrible experience anyway. So when I built my PC and I realized that legally purchasing a Windows license looked like browsing the black market, I decided to save my money and just try Ubuntu. I definitely had the luxury of being able to simply dive in.