Quick answer
Two images of stability, and only one holds. Wickedness may build something, but it cannot anchor it.
Read both lines
The contrast is between construction and rooting. The first line denies permanence to whatever wickedness erects, and the second answers with something living and underground, which will return at verse 12 as a root that yields fruit. The choice of image matters. A root is not impressive to look at and cannot be inspected from the surface, which is exactly the point: what makes a life immovable is not the visible part. This is the same claim the tree in Psalm 1 makes, and the same one this chapter's opening heading catches, that the house of the righteous stands.
Related: Proverbs 12:7 · Proverbs 12:12 · Psalm 1:3
New King James Version®, Copyright © 1982, Thomas Nelson. All rights reserved. Full copyright information. Scripture provided by API.Bible.
Go Deeper
If this verse has been used to put weight on you that it was never carrying, ask about it directly.