Pretty much, yeah.

There are multiple reasons to close a question, but fundamentally three categories: duplicates (which don't need to be changed unless you were misunderstood and a change would make it clear that you meant a different question); questions that can be fixed but require OP's private information to do so (e.g. expecting OP to focus on one question, or provide a proper example, or phrase things more clearly); and questions that fundamentally cannot be fixed (e.g. they're simply off topic).

Whenever a question can be fixed, it's expected that the asker tries to improve it.

But fundamentally the purpose of closing a question is to prevent answers to a question that doesn't meet the site standards. Where a question is fixable, this is only intended to last until it actually does get fixed.

> IIRC doing so automatically makes it eligible for reopening, without even having to ask.

It is immediately eligible for reopening from the moment it's closed. Sometimes people make mistakes.

But whenever anyone edits the question (including OP) there is a checkbox that can be used to assert that the edit resolves the problem, which puts it in a specific queue for consideration (otherwise, someone would have to stumble on it randomly).

> but if it's not caught by someone who knows about the older question the new one can become better

On rare occasions, there has been a deliberate organized effort to do a new question, because the old one was deemed simply insufficient (usually not a matter of becoming outdated, but simply failing to present and address the subject matter in a way that would be accessible to the target audience).