the.com/law of diminishing returns

means A principle stating that as you keep adding more of one input to a process, each additional unit eventually yields smaller and smaller gains, and may eventually yield none at all.

from Rooted in classical economics, especially the work of 18th and 19th century economists studying agriculture — they noticed that piling more labor or fertilizer onto a fixed plot of land kept boosting the harvest, but by smaller and smaller amounts each time. Early thinkers like Turgot and later Ricardo and Malthus wrestled with this pattern of land yielding less marginal benefit per extra effort, and the phrase 'diminishing returns' became the economists' shorthand for it. It later escaped the farm and the textbook entirely, spreading into everyday speech for any situation — pizza included — where more stops meaning better.