I think the points are:
- Yes, stud receivers are hard to replace.
- You don't have to replace one to one - multiple players can replace the production of one guy.
- It is easier to key on (give help on) two guys than it is to cover multiple guys who are all very capable.
In a 4 or 5 receiver set I know who I am going to key on when there are two guys on pace for over 1,000 yards and nobody else who is doing much. When you have 4 or 5 guys on pace for 600-800 yards there isn't a clear answer to who you are going to help on. Line it up and look to see which matchup(s) favor you.
Yes, everybody wants a stud receiver(s), but spreading the ball around to multiple very capable receivers also creates difficult decisions for defenses.
Not saying it is better, but just that it isn't cause for doom and gloom.