It's rare to see a team put a ton of money in one group. Generally that's going to be inefficient. Rams did it recently with Donald, Suh, and Brock.
So when you have a WR3 making coin it has a clear solution which is that trade. In fact if Woods wasn't so well liked around the league for his game he would have been cut. But thankfully they found a trade partner.
Now that money can be put to use on this roster elsewhere in plugging holes for the repeat run. And I am sure Kupp knows very well how good Robinson is. He knows this WR room just got a big shot in the arm.