Basically, yes. I came across a few comments that suggested it was great for audio UIs, but very unwieldy for anything outside that (things like non-Latin text rendering, navigation stacks, etc). So while it was possible to build general UIs in JUCE, you needed to go to a lot of effort (at least compared to something like Qt/Flutter/etc).

Admittedly I didn't dig really deep so I don't know how valid these criticisms are - so I was wondering if you had some tales from the trenches and how it stacks up against "less niche" UI kits.