It gives you the wedding you didn't see
You will spend your own wedding being moved between locations by people with schedules. Enormous amounts of it happen without you: the table that could not stop laughing during the second reading, your uncle teaching someone's toddler to dance, the twenty minutes on the terrace at dusk. A shared wall is the only practical way to get that back, because the people who saw it are the ones holding the cameras.
It costs your guests nothing to take part
Anything that requires an installation is a request, and on a wedding day you have already made a lot of those — travel, outfits, gifts, a day off work. A QR code that opens a page is not a request. It is a suggestion that takes four seconds to accept, which is why participation rates look nothing like an event app's.
It solves the seating plan problem socially
You have spent weeks on the seating plan trying to engineer conversation between people who have no reason to have any. A shared quiz or a guessing game does in ten minutes what the seating plan is attempting structurally — it gives two strangers a topic that isn't "and how do you know the couple?"
It keeps the DJ on your side
Wedding DJs are not resistant to requests; they are resistant to being interrupted mid-transition by someone who has been at the bar. Structuring requests is a favour to them, and a good DJ will use the queue as intelligence about the room rather than a list of obligations.
It doesn't need a host
Nothing here requires a compère, a facilitator, or a member of your wedding party to run it while missing the dinner. You announce it once, and it operates for the rest of the day without anyone owning it.