I myself now prefer to build admin tools on Java/Swing, because it’s much faster and easier than building a web app (Claude Code does that job quite well). Delphi probably offers even better dev.speed/quality/UX.
Of course there is electron, but that has its own set of complications.
For simple tools RAD is great.
I love the Flutter/WASM idea, but cannot get warm with the widget in widget approach flutter uses. Having a designtool like Delphi's would be nice.