With the continuous improvement of tourism infrastructure and the rapid development of digital platforms, tourism development is increasingly shaped by both traditional and digital factors. As one of China’s major urban agglomerations, the Urban Agglomeration in the Middle Reaches of the Yangtze River provides an important case for examining regional tourism development in the digital era. This study investigates 31 prefecture-level cities and develops a comprehensive evaluation framework covering tourism development foundation, platform visibility, and tourism market performance. The entropy weight-TOPSIS method, coupling coordination model, GIS spatial analysis, and optimal-parameter geographical detectors are employed to examine spatial patterns and driving mechanisms. The results show that Wuhan, Changsha, and Nanchang constitute three major tourism growth poles. Tourism development foundation exhibits a clear core–periphery pattern, while the overall coupling coordination degree remains moderate to low, with some cities characterized by high coupling but low coordination. Platform visibility is identified as a key factor contributing to spatial disparities and demonstrates a significant nonlinear enhancement effect when interacting with transportation factors. These findings highlight the importance of digital platforms in regional tourism development and provide implications for promoting coordinated tourism development within urban agglomerations.