I have all three browsers open on Mac OS with multiple tabs open in each. I measured the tab plus address bars of each:

    - Firefox: 79px
    - Chrome: 72px
    - Safari: 61px

You left out the most important case with only one/zero tabs where Safari gives up the space otherwise used by tabs and the other browsers don't.

That's about 90% of my browser windows and it makes Safari use only half as much space as the other browsers.