I think that seniority is closely correlated to understanding tradeoffs. Where a junior and a senior can make from time to time the same decision, how they do it is different. For junior it's often the only option he sees, or doesn't even realize he's making the decision that will have consequences. Whereas senior will think of the context and what are the possible options. All of them will be suboptimal and tradeoffs will be involved. And he'll pick the one that makes most sense with limited information from the context (tech properties, people impacted by the decisions, effort vs importance etc.).
...And senior's decision will unfortunately often be suboptimal as well, but that's what it is. He at least tried to understand the consequences and didn't have access to more information to evaluate it better. But he tried and will reflect on the failure and hopefully do slightly better next time at least in similar context.