Safari shows favicons in tab titles in macOS v10.14 Mojave.
It's a Safari 12 feature, so works on macOS 10.13 too.
Re:Why I’m done with Chrome
by geerlingguy on Sunday September 23, 2018 @11:55PM
(#18054900)
And Safari 12 on High Sierra.
I keep switching away from it due to lack of favicons and lack of extensions. I don't personally mind paying for a dev license to release an extension, but it definitely takes a toll on the extensions that get released.