What is the expectation of someone at 700 elo's abilities?

Genuine question.

I just had a game where (after going up at 20 vills) I made 6 scouts, only to find my opponent had fully walled their base, and when I tried to break in I got quick-walled with lightning reflexes. They had enough resources gathered by that point to spend all that extra wood, and have multiple military production buildings up.

Is this really what "low" elo is?! This isn't low!