#include <QLabel>
#include <QApplication>
int main(int argc, char** argv)
{
QApplication app{argc, argv};
QLabel label{"hello world!"};
label.show();
return app.exec();
}
$ g++ -O2 -g0 -fPIC hello.cpp -I/usr/include/qt -I/usr/include/qt/QtWidgets -lQt5Widgets -lQt5Core
$ du -csh a.out
16K a.out
The mechanisms are still there but the practice died when Qt stopped focusing on embedded targets.
Web-apps are architected fundamentally different than classical software.
That's not why these demos "Hello Framework" demos are 3-7MB though. That's due to the cost of shipping an entire widget system that takes complete responsibility for everything between raw user input to pixels on the screen, without using many of the affordances of browser APIs. This is really awesome for emulation, sandboxing, and preservation of software, but it's not a good route for saving bytes for the user.