"Worship leaders" are often just people who are good at leading the church members in songs. It seems to be more about making the church service look better and sound better. They aren't necessary and worship leader is a bit of a misnomer. Singing to God isn't what worship is.
Singing is about praises to God:
Colossians 3:16 KJV
16Let the word of Christ dwell in you richly in all wisdom; teaching and admonishing one another in psalms and hymns and spiritual songs, singing with grace in your hearts to the Lord.
True and proper worship is righteous living:
Romans 12:1-2 KJV
1I beseech you therefore, brethren, by the mercies of God, that ye present your bodies a living sacrifice, holy, acceptable unto God,
which is your reasonable service.
2And be not conformed to this world: but be ye transformed by the renewing of your mind, that ye may prove what
is that good, and acceptable, and perfect, will of God.
We should consider if the devil has gotten us to believe that singing a song to God on Sunday is what constitutes proper worship to God in truth and spirit. Have people been so easily led astray as to believe they have satisfied worship to God by singing songs and not righteous living? Think about it.