It was already mentioned by @RHOPKINS13 so I didn't bother.

As for Qt itself, I wasn't thrilled with their path regarding licensing back in the day, like only allowing GPL (not LGPL) on Unix like systems and attempting their own special licenses, and only offering a paid commercial license for Windows development. These days I can't say I find the $300+/month subscription option for commercial usage very appealing either. They can of course do whatever they want, just as I look at what is at my disposal and what's out there and choose according to my needs and preferences (which may be very different from other individuals). Essentially, their decisions early on soured my opinion of Qt (regardless of any technical merits), and since those days I have always had other options that have worked well enough for me. It may also have played a role in my relative lack of interest in KDE,

I'm just expressing my feelings, and it is not a statement whether anyone else should make any specific choices. :)