A search rank as proof
It came up first, so it must be the real one. This reasoning is so common that it usually goes unspoken, which makes it harder to argue with.
Bucket: NEVER
A search engine ranks pages by signals about pages. Links, text, behaviour, freshness. None of those signals is a check that an address on the page is correct, and no engine performs such a check for onion addresses because it cannot reach them.
What ranking actually measures
Roughly, how many other pages point at this one, how well the text matches the query, how people behave after clicking, and how recently the page changed. Each of those is a proxy for usefulness and each is available to anybody willing to work at it.
Nothing in that list is a measurement of the thing you care about. There is no signal for the address on this page is the one the operator published, because establishing that would require the engine to know what the operator published.
Why this is worse in this corner of the web
Competition for these queries is low and the reward for winning them is direct. That combination means the effort needed to rank is modest and the payoff for ranking with a wrong address is immediate. On an ordinary commercial query you are competing with well resourced sites. Here, often, you are not.
It also means the top result changes for reasons that have nothing to do with anything. A site can rise because another site fell.
What people get wrong
They upgrade ranking into endorsement, as though appearing first meant a check had been performed. No engine claims that. The interface implies an ordering of relevance and people read it as an ordering of truth.
They also assume consistency across sources means correctness. Ten sites showing the same awazon market url can mean the address is right, or it can mean nine of them copied the tenth. Copying is the cheapest way to fill a page, so agreement is weak evidence.
The freshness trap
Engines favour pages that change. A link page that updates its addresses weekly can rank above one that has been correct and unchanged for a year. Churn reads as maintenance to the machine and it reads as attentiveness to people, and neither reading is earned.
A page that changes its addresses often is either tracking real changes or manufacturing activity, and from the outside those two look the same.
Including this site
This page is not exempt. If you found this site through a search, the ranking that brought you here is exactly as meaningless as any other ranking. The addresses on the address page are not correct because a search engine sent you to them.
What you can do instead is compare across sources you arrived at independently, and hold on to a copy from a time you were not in a hurry. Neither is proof. Both are better than position on a results page.
What would move this
A search engine that verified onion addresses against a published, signed list and marked results accordingly. That would require an authority publishing such lists and an engine willing to reach the network. Neither exists, and the first would recreate the third party that onion addressing was designed to avoid.