> At least from the point of view of the interviewer, this was the point where they should give you a polite "hey, play along" nudge.

That may be the game, but we all know it's bullshit, and we shouldn't be playing along.

If a member of my team actually proposed building a bespoke system for something that can be straightforwardly done in a spreadsheet, we'd be having some conversations about ongoing maintenance costs of software