Concurrent code written with executors tends to leak two things: threads and intent. Structured concurrency addresses the second, and the first follows.

Scope as a lifetime

Forking inside a scope means the tasks cannot outlive it. If one fails, the others are cancelled; if the caller is interrupted, everything below is too. The shape of the code finally matches the shape of the work.

• A timeout on the scope applies to the whole fan-out, not to each call separately.
• Stack traces regain their meaning, because the parent is genuinely the parent.
• Partial results become an explicit decision rather than an accident of ordering.

It is one of those APIs that reads as obvious in hindsight, which is usually the sign of a good one.