This is how to enable it: https://lifehacker.com/how-to-enable-safari-favicons-on-mac-...
I do use Chrome during development though.
Safari lets you peek at the previous page, and makes it very obvious that you are about to go back, without any performance hit.
It also comes with reading mode, which chrome doesn't. Even with an ad blocker, many pages are still layed out in ways that can only be summed up as reader hostile.
So for reading and moving between pages, I feel like it beats both ffx and chrome. So I disagree with your "more important than anything else" part, but agree that performance and battery is among its top features, and if you don't care for that, safari does become a hard choice.
But it needs more than that when my battery already lasts 6+ hours under heavy use and my laptop is plugged in almost all day anyways.
Perhaps you can see how a reading mode that we already had extensions for in other browsers and sexier prev/next gestures damn it with weak praise.
As I said, it provides the best performance, experience and battery life.
To use Safari, you pretty much need to decide that performance / battery life are more important than anything else which only describes my needs when I need to milk my battery when it hits 10% with no electric outlet in sight.