I've contacted Safari devs and even created a bug report (marked as a duplicate a few days later) about that issue. The lack of an option to display favicons in Safari is incomprehensible, this small feature makes me unable to consider this browser as something else than the one I use to watch Apple keynotes.
For those of us with lots of tabs (e.g. more than a dozen), favicons are the only way to know what is in each tab. With only a letter or two showing, favicons are the only tab content identifier that exists.
However, my favorites/bookmarks bar is a row of favicons. I feel like The first Macs and Apple IIc did a great job labeling hardware ports with good icons. You could quickly understand what they meant, and worked better than words for the labels. I don't understand why Apple has decided that favicons are such an abomination that using them for tiny buttons in the favorites bar isn't even an option hidden somewhere in a plist.
Really, I just miss having favicons enough, that the advantages of Safari aren't enough to get me using it instead of Firefox.
Usually, when some Apple UI component baffles me, I find it's because they and I assumed different things about how the work should be done--so the friction disappears when I step back and figure out what the devs were thinking.
In this case, I think they believe the task of reviewing all open pages, and of finding a specific page that is neither nearby nor recent, are unsuited to the tab bar and better done with the Show All Tabs screen.
I suggest you force yourself to rely on Show All Tabs for a week, then reevaluate.
And after all, there is Chrome, Firefox, and many others that do have them for the ones that find them useful.