In Psalms 12 King David (the Psalmist) is writing. David is said to be a man after God's own heart (Acts 13:22). So obviously this is not referring to how all of the godly have ceased as if we are to read verse 1 with some kind of extreme form of wooden literalism here. We read elsewhere in another Psalm by David how he hides God’s words in his heart so that he may not sin against God (See: Psalms 119:11). Psalms 10:30 says, "The righteous shall never be removed: but the wicked shall not inhabit the earth." Proverbs 10:25 says, "As the whirlwind passeth, so is the wicked no more: but the righteous is an everlasting foundation."
Also, in Psalms 12: Consider that it says,
"....now will I arise, saith the LORD;
I will set him in safety from him that puffeth at him." (Psalms 12:5).
So the LORD setting at safety
him (the poor being oppressed by the proud speakers) is connected to God preserving them.
So again, God is preserving both the words and His people here.
Jesus said the poor will always be among you.
Also, consider that God's word does not return void (Isaiah 55:11).
But how is God's Word able to go out and not return void without a preacher?
Romans 10:14
"How then shall they call on him in whom they have not believed? and how shall they believe in him of whom they have not heard? and how shall they hear without a preacher?"