Earlier quoted context omitted.
The snarky „just don’t use Exchange, duh!“ doesn’t either. It’s a non-solution that armchair experts provide, who aren’t responsible for managing mailing for lots of people.
There is no alternative to Exchange that does not involve Microsoft?
Whether or not viable alternatives exist, those alternatives don’t magically change org structure, office politics, budget, current business priorities, etc.
Bottom line: many people managing exchange don’t have the luxury of evaluating this problem in terms of alternatives.