Quality survives use, not merely presentation.

Anything can be made to look right for the moment of presentation. What separates real quality is what happens on the hundredth day of use, under conditions nobody demonstrated, when the person using it is tired and not following the intended path. Durability is a different property from impressiveness, and only one of them shows up in a demo.

Judge things, including your own work, by imagining ordinary use over a long stretch rather than the first encounter. Ask what happens when someone uses it wrong, or when the easy conditions are gone. Build for that person, not for the one watching the first five minutes.