Why has installation been made more difficult?
I just jumped from Qt 5.6 to 5.9. I downloaded the Windows offline installer (first option on the Open Source landing page).
The default options for the installer don't include a version of Qt at all! So I ended up installing Qt Creator without any version of Qt using the 5.9 offline installer.
Kind of annoying for new users. What happened?
That's a question you should bring to the interest mailing list. You'll find there Qt's developers/maintainers. This forum is more user oriented.
Sounds good, thanks!
Did you download the Qt installer or the Qt Creator installer?
The Qt installer contains Qt and Creator, while the Qt Creator installer contains only Qt Creator without any Qt versions.