“Tight coupling however tends to come with higher efficiency—optimizing away the slack buffers and utilizing resources more fully—and therefore an economical advantage. Coupling can also be created to avoid some frequent low-impact events.
Specifically, the act of "going solid" is what happens when a generally loosely-coupled system reaches a saturation point and suddenly becomes tightly-coupled.”
https://cohost.org/mononcqc/post/888958-paper-going-solid