Exercise 3: Why Wrapping a Single Resource in a Module Can Be Premature Abstraction — Possible Solution
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A module exists to package a SHAPE that's reused, composed, or complex
enough to be worth naming as its own unit -- per the chapter, "reach
for a module once a shape is actually reused, or genuinely complex
enough to be worth naming." Wrapping a single plain resource, with no
meaningful logic beyond passing a few arguments straight through to
that one resource, doesn't do either of those things: there's nothing
being reused (it's called from exactly one place), and there's no real
complexity being hidden (anyone reading the module still has to open
it to see the one resource block it contains anyway).

What it DOES add is a layer of indirection: instead of reading the
resource block directly in the configuration, a reader now has to
follow a `module` block to a separate directory, open that directory's
own `main.tf` to find the actual resource, then cross-reference its
`variables.tf` to understand what each input argument does -- extra
navigation and cognitive overhead for something that, unwrapped, would
have been a single resource block sitting in plain view.

The tradeoff being made: the abstraction's promised benefit (reuse,
encapsulation, a stable "API" per the chapter's own tip-box) is paid
for entirely up front, in extra indirection and files, without ever
being collected, since the module is never actually called from more
than one place or hiding any real complexity. This mirrors a general
principle worth applying broadly: an abstraction should be introduced
because a task genuinely needs it, not preemptively, on the assumption
it might be needed someday -- three similar resource blocks are
better than a premature module wrapping just one of them.

WHY THIS WORKS AS AN ANSWER
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This identifies the specific two conditions the chapter itself gives
for a module being worthwhile (real reuse or real complexity) and shows
neither is met here, then names the concrete cost paid (extra
navigation/indirection) without a matching benefit, rather than a vague
"it's unnecessary."