Well we tried hard to build a great app, going through lots of mockups, user testing, research into how grandparents currently communicate with remote relatives etc.. and genuinely thought it could work based on the feedback.
Maybe there was never a product market fit in the first place, but the early feedback was that there was.
But maybe the product wasn't executed well and that's why it failed. Or there was an audience but it was far too niche.
That's the point, we just didn't even know why it failed.
We wouldn't use it to ask the users what to build necessarily (thought there are use cases for that) but more understanding why they DON'T like it...
even that would have given us a clear idea of what to change first and ignore the rest...