To be fair, this was always a problem, also with old computers and OSes. There was no link between pressing eject and magical things happening in the machine to commit data. The data was simply already committed so there was no need to have any additional layers of security.
The difference between then and now is that new computers have enormous amounts of memory and use it to provide write-back caching. This means the OS can tell applications that data is committed when it's not. This is an OS level decision which is done for performance and has nothing to do with the physical eject-buttons on your devices.
You may call this a small nit, but I think it's an important one. The eject-button on old machines would suffer the exact same problems if it used an OS which offered write-back cache.
You could say old Macs didn't have this problem, which is true. But it didn't have an eject-button. It relied on the OS doing that. And then instead you had the problem of people not being able to get their disks out of their machines if the OS for some reason refused to release it (or that users didn't realize they had to drag the disk-icon to trash).