The sharing economy offers potential economic, social, and environmental benefits, yet participation is not universal. Our research, based on a survey of 873 individuals across three generations in the Czech Republic, investigates the barriers that limit engagement and how these vary across different generations. We examine supply and demand side barriers, identifying four key components on each side (Principal Component Analysis). On the supply side, these include user uncertainty, personal uncertainty, uncertainty from lack of information, and uncertainty from the platform. On the demand side, we identified user uncertainty, personal uncertainty, uncertainty from perceived value, and uncertainty from operational risks. Our findings reveal significant generational differences concerning these barriers. On the supply side, the first three components show statistically significant differences between generations. On the demand side, we found substantial differences for the second and fourth components. The implications of our research suggest that peer-to-peer platforms could benefit from employing generational marketing strategies to address these barriers, thereby increasing their e-commerce volume.