> they are just mostly finished

Yeah, I don't know how much experience you have with Qt but widgets are far from being "finished". There's plenty of things that could be improved if their focus wasn't on Qt Quick.

The use of Qt Widgets is declining (albeit slowly), as stated in http://blog.qt.io/blog/2019/01/14/qt-customer-survey-2018/. You're telling me that they're going to support two different technologies that do the same thing without giving preference to the newer, technically superior one?

Qt Quick is intended to replace Qt Widgets, but it isn't currently at a stage where that's feasible -- hence my apprehension.

Yeah, that's not true. They have said that Qt4 widgets are feature finished, and not being deprecated. Obviously eventually there will be little use of the older way, but they have repeatedly said they are not deprecating them. Believe what you want.

I'm aware that they aren't being deprecated, but that doesn't mean they aren't being phased out. When I say it is being "phased-out" I'm referring to how it will no longer be advertised as the optimal solution to a problem. Perhaps we're just arguing semantics at this point?

You can use the tool until it's deprecated. Everything is constantly being "phased out".

Phasing out is the same as sunsetting, i.e., terminating: https://whatis.techtarget.com/definition/sunsetting

From the first post, I assumed the commenter meant something like, "in Qt 6 QWidgets will stop working", which is insane.

I guess it was poor wording on my part then, sorry. I only meant that it was not going to be the focus of the product anymore.