Before any of it
— and the same five things get very easy to assume:
the vision
An entire ecosystem, for everyone we can picture.
the market
The trend is huge, so demand must be too.
the depth
We looked into it. Briefly.
the user
Someone needs this. We didn't ask who.
the mvp
Even the minimum needs every feature.
Downstream, every one of these looks like a UX problem. It never is.