Firefox natively suspends unused tabs which dramatically improved my memory usage and battery life.

Chrome has a similar extension but it's nice having it built in to the browser natively.

If anything you could argue that FF is behind Chrome security-wise with their more limited sandboxing and some other memory protections. But performance is largely a non-issue.

Not for me, because Firefox's reader view stops the entire battery sucking JavaScript madness on the page I'm visiting whereas Safari doesn't.

Everyone "lags behind" Safari in battery life on mac, unsurprisingly: a mono-platform app can pull tricks that multi-platform ones cannot.

When comparing apples to apples, Firefox imho is actually lighter than Chrome on battery, at least on Macs.

Understandable from perspective of how apps are developed, but from the user perspective comparing Firefox on Mac to Safari on Mac is literally comparing software on Apples to software on Apples.