Quick answer
Money attracts company and poverty scatters it. The verse reports how this works without pretending it should.
Read both lines
The two halves are not balanced, and the imbalance is deliberate. Wealth gains many friends; the poor man loses the one he had. That singular is devastating, because it means the loss is not statistical but personal, someone specific who used to be there. The verse belongs to a short run on money and friendship that surfaces again at verse 6 and verse 7, and Proverbs is describing a social mechanism here rather than endorsing it. Read as a fact about human behavior, it explains a great deal about who calls and who stops calling. Read as a rule for choosing friends, it would recommend exactly the behavior the chapter goes on to condemn.
Related: Proverbs 19:6 · Proverbs 19:7 · Proverbs 14:20
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.