Aroung the 8 minute mark you say to press the 'Alt' key to change multiple values. 'Alt' key prevents any value from being changed instead of allowing multiple values to change. Without the 'Alt' key being pressed only the active element is affected. With 'Alt' nothing can be changed.
Maybe you can't see it, because you need to enable the Emulate 3 Button Mouse first...???
The feature has been around for quite a while now; in the earlier versions it was visible at all times, like in 2.83, but maybe in more recent versions they changed that...
As you can see in Omar's first screenshot, it wasn't there, but in his second one, it was...
...Or wait, the first one was from Windows and the second from MacOS....
But we don't get the extra juicy graphics card... ;)
Unfortunately the OS key is too far off the way for my small hand with bad tendons, so I found another way around it (in case it can be used to someone): apply the change once, then select all others, right click and copy to selected.
