The fact is that a viable, efficient, native and cross-platform GUI solution has failed to emerge. Note the word 'viable'. Those who might suggest that Qt covers that role have to explain why, even though it has been capable of fast, attractive apps for a long time, nobody built Slack, Discord, Atom or VSCode in it.

This is the point about Clojurescript too: yes it compiles slower and runs slower, but it allows access to what is essentially the world's largest and most complete UI framework, known as the browser. That makes apps cheaper and faster to produce, at the cost of sluggish/bloated performance. The market has indicated that this is an acceptable tradeoff. Until some other solution can match it on these axes, Electron/Javascript/React SPAs will dominate.

I work with a Qt-like C++ GUI framework (JUCE), but we've seen increasing portions of our front-end work replaced with Electron/React Native. It saddens me to see binary sizes and memory consumption balloon, because native development encourages you to care about these things. But even I cannot deny the order-of-magnitude improvements in productivity from hot-reloading, a deep (if byzantine) system for styling and layout (including text), and reuse of modular components across all platforms.