That may be technically true, but programs using the std containers have to convert at some point if the data has to show up in the GUI. There may be some really clever ways to avoid a bunch of copying and string conversions, but by default there will be a bit of overhead converting back and forth.

I'm not sure what you mean by "Moc is not a problem anymore, ...". AFAICT, Moc is still used by Qt and is at least still in their documentation. http://doc.qt.io/qt-5/why-moc.html I'm personally not too bothered by Moc and see it as a trade off of using Qt. I'd prefer a cleaner "pure" C++ solution, but I don't know of any GUI toolkits as nice as Qt without Moc.

Qt is still my preferred GUI framework, and I use it from C++, Python, and lately Common Lisp. My biggest complaints are the way it's been increasingly tied to Qt Creator and the focus on Qt Quick and QML.