The "Anaconda Plan" got a bad rap from all the people who thought that victory was about elan and aggressive, heroic dashing cavalry charges. But Scott's plan really did end up as the backbone of the eventual Union strategy that won the war.
Scott's plan (whether he knew it or not) was a plan based on the idea of total war in which degrading an enemy's economic capacity is as important as attacking its military.
By blockading the South by sea, the Union was able to severely degrade its ability to trade with Europe and even within its own borders. This made it much harder for the South to prosecute the war. The same thing became true when the North was finally able to take Vicksburg in July of 1863 and secure control of the entire Mississippi.
Now, Scott's plan would never have worked to win the entire war. Just as the idea that strategic bombing can win wars today is fantasy, so was the idea that blockades alone could win. So Scott's plan was not sufficient to win the war, but it was certainly an important part of the winning strategy.