Lee Carré (2021-06-06 11:44:13+00:00): Then the wiki is misleading, especially for newbies. Though it's not the first instance of inconsistency I've found. Another is craft=pottery versus shop=pottery, but I'll address that one separately.
Might I suggest that an experienced contributor, such as yourself, correct the misleading info in the wiki.

My thinking was around (semantic) correctness (while avoiding ambiguity), rather than doing (sheep-like) whatever's popular. I recall reading the documentation advocating for correctness in data, rather than working around renderer glitches and the like (I would imagine that what editors recognise would be included). I notice that a number of proposals relating to tagging schema, which have since been adopted, were lodged in order to escape & avoid problems of ambiguity.

I also have to wonder how any new proposal comes into effect (or simply defacto usage), if only already-popular tags are acceptable. Nevermind ad-hoc pre-proposal improvisation for unforeseen scenarios (shop=virtual perhaps?).

Thus, this is an argument-from-popularity fallacy.

Disused:* doesn't convey what I observed during survey. Vacant:* does.
I read the wiki article you cited, and others (as I said; before making my change), and based on what they said it seemed that the intended use-case for disused:* would be something like a decommissioned phone or post-box. Though, yes, it's easy to allow scope-creep.
Compare a house which is currently unoccupied. It remains a house, it hasn't been marked for demolition or repurposing (i.e. a use other than residential). It's simply vacant, but likely to be occupied once more.

Same with the PoI here; it's still a retail space, it's not being converted for another use (i.e. disused as retail space), but simply between occupiers. Though, appears that it's awaiting another to move in.

There's no construction work, to alter it, either. Nor is any planned (else a notice would be posted, as legislation / regulation requires).
Nor is it boarded-up or such.

Unless you noticed something which I missed, during your survey?

“shop = vacant and vacant = yes”
The wiki specifically said to avoid this (and gave reasons), just like with shop=disused, and even if it hadn't recommended vacant;* instead, that would be logical considering the other prefixes, and there appearing to be a consensus of preferring to add prefixes rather than replacing either key or value.

“"vacant:shop" is used 60 times world-wide (likely due to the one line in the Wiki you found on the "shop" page).”
From http://taginfo.openstreetmap.org/keys/vacant%3Ashop I presume?

While http://taginfo.openstreetmap.org/keys/disused:craft occurs only 264 times globally. Also ‘unpopular’ (hardly common).

Meanwhile, http://taginfo.openstreetmap.org/keys/vacant occurs 3134 times. This is comparable to some of the lifecycle prefixes regarded as common (such as ruins:*).

I could also cite http://taginfo.openstreetmap.org/reports/frequently_used_keys_without_wiki_page

“There are no other use cases of "vacant:*" with other tags to be found.”
Yet, http://taginfo.openstreetmap.org/search?q=vacant%3A clearly shows that there are.
Unless you meant prescribed or intended cases described by the wiki?