I have yet to use a JVM based GUI that felt snappy. JVM based language benchmarks are always really good, but somehow that never translates well to GUIs
There is a culture of gaslighting about it (JVM and similar); point out that you observe something being slow and it will be dismissed with "first, run the code several times to warm up the JIT, then carefully select the points where you time to make it look faster". For example this "Dijkstra path finding in C# is 15x slower than C++ version"[1], the question says "the C# algorithm takes 38ms to find a path. The C++ version takes just 2ms" and the accepted and much upvoted answer begins "First of all, you should run the FindPath method a couple of times before measuring, to give the C# runtime a chance to optimize the code. [...] Doing this gets the time down to about 17ms on my machine (from 38ms initially)."
So maybe if you want a keypress that responds quickly you should press that key a few times, wait for the editor to respond, delete it, then press it again and you'll see how fast it really is. Seems to me this is tied in with the "lightning fast" claims here and the sneering dismissals in the comments "that doesn't mean ANYTHING"; it's a secret message which means "not heavyweight laggy Java". It's the Python-to-Java's-boilerplate, the Agile-to-Big-Design-Up-Front, the Go-single-binary-to-Python-virtualenv, a calling card rather than a specific performance claim.
They have made a custom UI framework based on skia rendering engine. Skia is used by flutter, Chrome and firefox for rendering and known for great performance.
So maybe if you want a keypress that responds quickly you should press that key a few times, wait for the editor to respond, delete it, then press it again and you'll see how fast it really is. Seems to me this is tied in with the "lightning fast" claims here and the sneering dismissals in the comments "that doesn't mean ANYTHING"; it's a secret message which means "not heavyweight laggy Java". It's the Python-to-Java's-boilerplate, the Agile-to-Big-Design-Up-Front, the Go-single-binary-to-Python-virtualenv, a calling card rather than a specific performance claim.
[1] https://codereview.stackexchange.com/questions/152733/dijkst... (the answer is otherwise very detailed and interesting)