Obviously this is on the desktop. If you want a presence on the desktop, you have to own the OS like Windows, macOS and Chrome, unless regulators force a choice.
As opposed to what? Mobile is worse, with iOS not allowing a choice at all.
You can change browsers, just not browser engines. This might bother me if any other browser engines seemed to give a damn about battery life, but since they don't, it's justifiable for the reason of preventing people from "mysteriously" having terrible battery life because ads on Google properties convinced them to install Chrome, at least.
What makes you say IOS does not allow a choice? I’m writing this from Firefox on an IPhone?
How does Chrome own the OS? ChromeOS is hardly what's making Chrome the dominant browser.