Globally equitable access to safely managed drinking water and sanitation is one of the major aims of the United Nations' Sustainable Development Goals, specifically SDG goal 6. We assessed global-scale progress toward this goal from 2000 to 2020 with access rates to improved drinking water and sanitation services that are adjusted for socioeconomic, political, and hydrological conditions. We found that the adjusted access rates in 2020 were lower than 2000, although not-adjusted access rates had increased. Access rates improved more slowly in higher-GDP countries than in lower-GDP ones during this period. These show that access rates in lower-income countries improved, but were still lower, compared with those in countries with the same social conditions in 2000. This suggests the recent progress toward this goal has not aligned well with social development, emphasizing need for reflecting national management, international cooperation, and investment in water-related infrastructures to achieve the goal by 2030.