Quick answer
Decisions made alone go wrong more often. The verse recommends numbers, not because crowds are wise but because one perspective has blind spots.
Read both lines
The setting is national rather than personal: a people falls for want of guidance, and the word behind "counsel" carries the sense of steering or direction. The second line's remedy is plural on purpose. It is not one brilliant advisor but a multitude, which assumes that any single view, however good, is partial. This is one of the most practical verses in the book and one of the least mystical. Safety here is a function of having enough people in the room to catch what you cannot see.
Related: Proverbs 15:22 · Proverbs 24:6 · Proverbs 20:18
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.