If I think a single research is meticulous enough to clarify a subject, is it right to only cite that one article?
The one I'm interested in references previous work, so there would be different sources, but it's still one single starting point.
Here's how personally I see it:
We have a range of sources of information, in which we put a differing amount of trust. Here is a rough ordering. (I am sure it could be debated and enhanced, but it is just for illustration.)
We have minimum quality standards here that forbid evidence that is personal anecdotes or below. We look at anything below peer-reviewed experiments with some leeriness.
The job of the answer is to address the claims of the source in the question, and address them with evidence that is higher in trust.
Ideally, that would be from the top of the list, but often that's not available, and we have to resort to lower quality sources.
I would offer this question as an example: Do McDonald's burgers have an unnaturally long lifespan? It is a question unlikely to be examined by an expensive lab. Nor is the answer (which is predictable by food scientists) likely to earn a place in a peer-reviewed journal.
Questions about history and attribution of authorship also tend to require answers from sources lower on the totem pole.
However, we should be offering better quality evidence than the original source.
I recall a question (I can't find it now - I think it was about fluoridation.) where I answered citing a single experiment. The OP pointed out the existence of studies with opposite conclusions - demonstrating the dangers of relying on a single study! I had to fundamentally rewrite my answer after doing more research - I found meta-analyses that included the cited studies, and made a much stronger case for the original conclusion.
So, to answer the question:
Edit: Here is someone else's attempt at the same idea of an evidence hierarchy:
Yes. Sometimes that’s the best there is.
Other times, on the other hand, a single source is trumped by multiple, aggregated results. Use judgement.