Most users have no idea how much memory a piece of software uses. They care about user experience though which means they will care if the UI hangs or is unresponsive.
Bingo. I’d go further and say they don’t care about your application at all. They just want to do something, and your application’s quality is measured by how little it stands in the way of accomplishing that.
The sad fact is this encapsulates features (ease of development, a framework probably does help you ship faster), adaptability (clean abstractions that are easy to work with), and performance.
Finding that balance is always going to be hard but they’re all important!