There's a certain no-BS authenticity about sites which choose this aesthetic, that I and many others appreciate. But you raise a good point, that the look can

There's a certain no-BS authenticity about sites which choose this aesthetic, that I and many others appreciate. But you raise a good point, that the look can also make people think they're seeing an old site, which lacks current utility and fresh updates. So a suggestion to the creator (and others choosing this spartan sensibility): balance the plainness with some other prominent indicators of freshness. This might include "last updated" dates, including the year, in prominent places. And, even where info is not changed for years – because it remains valid – add other indicators that it's still current. (This might be a "Reviewed" or "Valid through" date that's never more than a few months old.)