Use of fertilizers and weed controls is the foundation for a healthy lawn
The foundation of a healthy lawn is healthy soil. What makes a soil healthy is its texture and structure. A healthy soil will allow water, air, nutrients and roots to move through it with ease. It's filled with good stuff like microorganisms, worms and other beneficial life forms. Without sponge-like soil, it is like treating the symptoms (with weed controls and over-fertilizing), rather than getting to the "root" of the problem.