Ceiling or rough patch
The first thing to figure out is which one you're actually in, because the two look identical from the inside and require opposite responses. A rough patch is circumstantial: a hard project, a difficult stretch with a manager, a season of burnout that a real vacation would meaningfully dent. A ceiling is structural: the role has topped out what it can teach you, pay you, or make possible for you, and no amount of rest changes that math.
The test that actually distinguishes them: imagine you took three real weeks off, fully disconnected, and came back. Would the thing that's bothering you be gone, or would it just be waiting for you, unchanged? If a break would fix it, you're in a rough patch, and quitting would be solving a temporary problem with a permanent decision. If you can picture the break clearly and the flatness is still there when you get back, that's not fatigue talking. That's the ceiling.
Why we wait for permission that never comes
Most people who are in this position wait for the situation to get bad enough to justify leaving, as if you need a certain quantity of misery to earn the decision. That instinct is backwards. Waiting for it to get worse means you're optimizing for having a good story to tell people, not for your own trajectory. The people who navigate this well leave from strength, while things are still good, because the ceiling was clear and there was no reason to wait for it to start actively hurting.
This is also why these exits are lonelier than the obvious ones. Nobody's going to validate the decision for you the way they would if your manager were a nightmare. Colleagues will be confused. "But it's going so well for you there" will get said, more than once, by people who mean it kindly and are also missing the point entirely. You have to be the one who's convinced, because you won't get outside confirmation. That's not a sign you're wrong. It's just what a ceiling decision looks like from the outside, where the evidence is invisible to everyone but you.
If you've done the three-week test honestly, and the flatness held, the decision doesn't need more evidence. It needs a plan and a date. Waiting for certainty you'll never receive isn't diligence. It's just the ceiling, in disguise, buying itself another year.