My guess is that when Apple got rid of the ODD, they tossed the eject button at the same time.
That together with shrinking the keyboard size to match that of the MacBook/MacBook Pro which leaves little room for extraneous keys.
Eject "buttons" can easily be added to the Finder Task/Menu bar OR using a right click/contextual menu on the mouse.
There is no need to add them, simply attach an external ODD, insert a disc and
voilà - an eject button will automagically appear on the menu bar,
- a dismount/eject icon appears by the mounted disc in the Finder sidebar,
- eject is on the context menu for the mounted disc (there is no icon or context menu for the drive itself, only the disc in the drive).
- click on drag the mounted disc icon to the trash and that ejects it from the drive
- I suppose it could be added to the Touch Bar on MacBook Pros that are so equipped, but the app developers have yet to do that.
This is consistent with how MacOS deals with any device, if it isn't present the drivers and any associated functions are simply not loaded. If you think about it, it isn't the physical ODD you want to eject, it is the disc in the drive. In fact the only way to eject the
drive is to physically disconnect it. The disc is the only thing that can be ejected or dismounted. It is the ODD manufacturers who have removed the physical eject button from the drive, not Apple (albeit most likely at the request of Apple, HP,
etc.). There are still some (a few?) external ODD enclosures that have a physical eject button but I haven't seen a paperclip hole for a while now.
