That JUCE is "heavily used in gaming" for starters is widly innacurate
I know it's tangential to the point that you're making, but JUCE was acquired by PACE in 2020.
There may be some people you know using JUCE for games, but it’s an odd choice.
Trying to figure out what you might mean, JUCE was involved with the BLOCKS SDK for Roli’s hardware peripherals, but again, that’s not really about gaming and definitely not about any familiar kind of gaming.
That said, I’m sure you’re relating the best information you have and very likely just transposed some detail by accident and are now caught in a relentless, exhausting online nitpick. We’ve all been there. If you figure out what it was, I’d love to hear it!
The kind of games some tint amount of people make with JUCE is like this: https://ankuznetsov.wixsite.com/jucegames and even those are few and far between.
In any case, nowhere even close to "widly used" in gaming. Nor moderately used, or even low use.
"Few and far between users of JUCE for games, and even at that almost all of them using it for hobby casual game projects" is an accurate description.
JUCE does dominate in audio VST/AU fx/instruments GUIs though...
Also, you can use OpenGL for GUI compositing, too, not only as a 3D context.
https://github.com/juce-framework/JUCE/blob/4e68af7fde8a0a64...
You’d surprise a lot of people if you were right about it using GPU acceleration for its UI framework. It does have an OpenGL container that fits into its view object hierarchy if you want to write your own accelerated component, but the rest of the UI is pretty much standard event-loop -> platform-API dispatch. It’s accelerated where the underlying platform-API is accelerated but not in any kind of explicit or fine-tuned way. The focus has always been more on portability than performance, even on the audio side.
(And of course the high-priority audio processing runs in an entirely segregated context from the UI, so the performance characteristics of the two pieces are decoupled anyway.)