Anjani Kumar SI is still very common in cross-pollinating crops such as brassicas. You can find some comparison between SI and MS at https://www.biologydiscussion.com/plant-breeding/self-incompatibility-male-sterility-in-plants-plant-breeding-botany/80638
The availability of compatible pollen at the right time requires careful timing and coordination between different plants making the hybrid seed production process more complicated for self-incompatability.
Self-incompatibility is not commonly used in hybrid seed production due to its complexity in management, inconsistent pollination influenced by environmental factors, limited applicability to certain crops, labor-intensive processes, and potential for lower seed yield. More reliable methods like male sterility are preferred for large-scale hybrid seed production.