How easily people move through the org, and whether the movement goes toward the highest-leverage problems. Stagnation isn't just an HR issue. Stuck people do stuck work.
FLUID VS STAGNANT
Strong performers go where they're needed. Internal mobility is common enough that it's not a big deal. The best stay because they have room to grow, not because leaving is difficult.
The best performers eventually calculate that their leverage is higher somewhere else and leave. What stays behind is a selection effect. The org gets more calcified at every level.
Organizations don't fail from bad people. They fail from the gradual concentration of people who've run out of reasons to try. That concentration is the signal.
Low talent flow looks like a retention problem. It's usually a mobility problem. When people can't move to different work inside the org, the only signal available to a high performer is to leave entirely. The best self-select out. What remains increasingly self-selects for compliance over capability. The org hires harder to fill the same hole.
Squad model with fluid membership. Moving between squads is a normal career move, not an exception that requires HR approval.
Internal transfers are a legitimate career path. Talent gets routed toward problems, not locked into org boxes.
Wage compression and legacy culture make internal mobility difficult. High performers calculate that their leverage is higher somewhere else.
Post-merger org has multiple competing power structures. Moving between them requires political navigation, not just performance.