Short answer is yes, the use of JUCE is very widespread in audio / music software.
A few issues you might run into:
The VST2 license is no longer available for new developers (which compile into .dll files), VST3 plugins compile as .vst3 files, but im sure your host has probably set up compatibility with the new standard by now.
I might be wrong about this but I’m not entirely sure about MIDI processing capabilities with the VST3 standard, there have been a few threads on the forum regarding it, such as this one.
I started learning C++ with JUCE, and I don’t think that it would be too difficult to learn if one is already experienced with C++ as it’s just a framework.