Worldwide, and especially in developing countries, agriculture  is the largest water user, accounting for 50-90% of all water use. Moreover, a substantial part of the water used in agriculture is 'consumptive' use, which means that the water is 'consumed' for crop growth and is not immediately available for other uses. This is different from other sectors, such as energy production, where only a fraction of the water is consumed, and other downstream users can reuse the rest. Agriculture also accounts for a large share of employment in developing countries, with 60-80% of the rural population dependent on agriculture for their livelihoods. Agriculture provides food security for all. This makes farmers and agriculture particularly vulnerable to climate change.
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report