macOS has supported this for many years, but you have to turn it on.
Open System Preferences (if you’re using macOS 13 Ventura, I think Apple changed the name of this to Settings), open the Keyboard settings, and click the Shortcuts tab. Enable the option “Use keyboard navigation to move focus between controls.” When that’s enabled, you can use the Tab key to reach the Format menu in the Save As dialog box. (When disabled, macOS has the Tab key move only among editable fields.)
This works in the Save As dialog box because that’s a macOS native dialog box. It does not work in many other Photoshop dialog boxes (such as Image > Image Size), because Adobe seems to have built those with its own UI code, which doesn’t respect the macOS setting for Tab key navigation. In those Photoshop dialog boxes, Tab can move only among editable fields.
You might notice in the screen shot above that macOS also provides keyboard access to the menu bar and Dock similar to how Windows does. If you use those features, you can use arrow keys and type-ahead to select menu commands and other items.