Read with verse 6, which makes the same observation from the other side.
Quick answer
Correction said out loud beats affection kept quiet. The verse is comparing two goods and says the visible one wins.
Read both lines
The comparison is not between rebuke and love, which would be a strange contest. It is between love that has been made visible as correction and love that stayed hidden, and the second half is doing the work: carefully concealed, deliberately, by someone who has it and did not say it.
That is the verse's actual complaint. Concealed love is not neutral, because the person it belongs to receives nothing from it. A rebuke at least arrives. What the saying assumes, and what makes it safe, is a relationship where the rebuke comes from love in the first place, which is exactly what verse 6 states.
Related: Proverbs 27:6 · Proverbs 28:23 · Proverbs 25:12 · Proverbs 15:31
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.