Lots of people in certain countries think that agriculture should be developed in order for them to be rich. This is a misguided opinion.
Thailand is a good example of the fact that when it generated a per capita income of close to USD 3,000 about 18 years ago, it faced obstacles to increase this income. Main reasons: 1. Agriculture produces food, and people consume it to a certain amount, not more; 2. Agricultural products are commodities, so their prices are sensitive to supply and demand. For example, if supply exceeds demand by a mere 5%, product prices can go down by 20%.
So, from about 2002, Thailand has been aggressively developing its manufacturing sector so that the country now is the largest automobile manufacturer and exporter in ASEAN.
Another reason: the contributions of agriculture to the GDPs of developed nations such as the US and Japan range between 1% and 1.3% only.
Like Japan and most other developed countries, the US got rich because of its manufacturing might. The US generated around 40% of the world’s GDP from 1960 to 1968 (https://www.forbes.com/sites/mikepatton/2016/02/29/u-s-role-in-global-economy-declines-nearly-50/?sh=5ce3afcc5e9e). The ratio of its GDP to the world’s began to decline from 1969. This ratio now stands at about 15.9% only (https://www.statista.com/statistics/270267/united-states-share-of-global-gross-domestic-product-gdp/).
About the Composition of Japan’s GDP today
China is the most recent example of how a developing country can get rich: from investment in productive physical assets, manufacturing and exports of finished products.
CAVEAT: Certain individuals and businesses have got so wealthy from large-scale, or commercial, or cash crop, agriculture. For example, Robert Kuok, owner of Shangri-la hotels, sugar & oil palm plantation king & the richest person in Malaysia and the 53rd wealthiest in the world in 2020; Martua Sitorus, one of Indonesia’s oil palm plantation kings & the county’s 12th wealthiest; the big commodity traders: Archer Daniels Midland (ADM), Bunge, Cargill & Louis Dreyfus, known as the ABCD of global grain trading, of the US. They play central roles in the global agri-food system (https://www.reuters.com/article/us-global-grains-traders-idUSKCN1MZ2E8).