Why hasn't Java added an option for automatic heap sizing for the desktop application use case (or any use case, for that matter)? Seems like a no-brainer thing to add, so I guess there are Reasons(tm).
It has. Modern JVMs can use as much memory as they "need" to, but for some reason JetBrains don't use this feature. I think after they upgrade to Java 17 they'll get it. But this has really killed their brand for a long time. 99% of the time people complain about their IDEs being slow it's because the app is GC thrashing and burning CPU rather than increase heap size.
I was under the impression that every gc still defaulted -Xmx to 25% of available memory.
It is configured by jetbrains (I guess to not use as much memory as Java would default to)