A lawn is a community of living plants, not a carpet. Mowing removes leaf, while the remaining plant must support new growth and roots. The right care depends on the grass, conditions and what you want the area to do.
A play surface, a closely cut ornamental lawn and an area allowed to flower have different priorities. Moss or low flowers are not automatically failures. Decide which qualities matter before treating everything except grass as a problem.
Mowing can help maintain a usable surface, but it is not necessarily a weekly job. Observe growth and conditions first. The safety lesson applies to the mower, the work area and any later soil work.