Google seems to be putting huge amounts of effort on Flutter, and it can already run on the desktop (still early stages and in alpha I believe)... JavaFX is mostly orphan right now. Oracle seems to have no interest in it... so it seems to be currently being mostly advanced by Gluon[1], which honestly, does not have the muscle to pull out something competitive with Flutter or Electron.
JavaFX still has fundamental pieces missing... like setting an icon for the app or opening some URL in the system browser[2] (without using horrible hacks, which is what I've been doing - which get you lots of warnings since the module system was introduced, and may stop working soon). Not to mention no support for auto-updates, the fact that jpackage is still in "incubator" stage[3] and intentionally does not have JavaFX-specific features at all (it's just barely usable with JavaFX), the SceneBuilder, which could be such a great tool to develop UIs, similar to Lazarus, but it's nowhere as good, being in about the same unfinished state it was in around 2014, terrible documentation and lack of adoption (most examples you find online are from circa 2015, when JavaFX got a little traction)...
These things all make JavaFX a very hard sell for non-developers apps (if you're a developer who does not mind installing the appropriate JVM version to run the app, JavaFX works quite well - a 1MB jar can give you A LOT of features - one of my apps, my favourite and really useful, is only a 340KB single jar and works on any JVM 8+ - and looks as modern as any Electron app).
It's sad but the best way to get professional apps developed and distributed nowadays seems to be, by far, Electron (because of JS, and its stupid browser-based architecture)... but I am hoping Flutter will break Electron's hegemony soon as I have great experience developing Flutter apps on mobile and the web... Just try the online pad[4] to get a taste of what it looks like! It's amazing.
[1] https://gluonhq.com/products/javafx/ [2] https://bugs.java.com/bugdatabase/view_bug.do?bug_id=8091107 [3] https://openjdk.java.net/jeps/343 [4] https://dartpad.dartlang.org/ecb28c29c646b7f38139b1e7f44129b...