Depends on how long you go between mowing and how high you set your mower. Most folks cut too low, water too much, and fertilize too much.

For a well established lawn, I set my blades to 2 inches (5 cm); mow when the grass is at or just below 3 inches; and NEVER bag the cuttings. I do not fertilize and even during the current exceptional drought we've been having in the SE US, I do not water my lawn. With regard to mulching, I've heard it said that mulching will build thatch...BS, pure and simple. Clippings decompose very quickly and add right back into your lawn all of the nitrogen that (if you bag) you need to reapply using chemical fertilizers.

A watered, fertilized lawn will produce the vast majority of its feeder roots in the top 1/2 to 1 inch of the soil because that is where you're putting all of the things it needs. By not watering or fertilizing, your lawn will put its root system deep into the soil so that it can extract water and nutrients from the soil profile...depending on your local conditions that may be up to 4 feet deep! A healthy lawn will not be affected by most insects or diseases. Most lawn diseases are caused by overwatering (fungal problems such as brown spot or dollar spot) or by too much nitrogen (grubs). It is in the interest of landscape companies and fertilizer manufacturers for you to water and fertilize too much. Save yourself a bunch of labor and money. Wean your lawn off the water and nitrogen.

Just another data point,
Ed