Clearly you don't work for one of the largest companies in the country.
It’s not the point. There are a time and place to use everything. Reply all is on the most part an extremely important part of the email feature.
Same way you tell some people to come into the meeting just to hear what is happening but not necessarily to comment. Or a secretary to know what is going on.
The real annoying guys are the ones that when I copy someone specifically and they don’t reply all. It can happen with the same guy in one thread many times. I keep adding them back when I respond and they just press reply.