I recently updated my Mac to Mojave -- yea, just days before Catalina was released! I did this for a few reasons, but mostly I was unsure if JDK 11 would work on the macOS I was running and I needed JDK 11 for some consulting work. Since updating to Mojave I have found both NetBeans 8.2 (using JDK 8) and Apache NetBeans 11.1 (using OpenJDK 11) to be unstable. They don't freeze, but parts of the interface just stop working after a few hours of use. Mouse clicking fails in some places. Some keyboard commands fail. Typed input fails. The only solution is to restart NetBeans. This is not a good nor long term development environment tactic.
I have been worried for some time that Java on the Mac is at an end. Apple abandoned Java back in 2017. I didn't expect Oracle or anyone else to really put much effort into keeping the Java GUI toolkits current with macOS changes. I don't even expect Java GUIs to remain for much longer, either. JavaFX was dropped in JDK 11. I am sure Swing would have gone too if it were not for some very important customers that are still dependent on it, for example, the US military and especially the Navy.
I have similar observations about NetBeans. NetBeans always seemed like Oracle's unwanted stepchild from the Sun acquisition. Updates were infrequent and with little innovation. Oracle has now passed it on to Apache, but how much attention is it going to get there? There are commercial applications that are built on top of the NetBeans platform and so some support will come from them, but it would be foolish for these commercial applications to remain desktop bound for too much longer. Even Eclipse, the quintessential Java tool for building Java tools, has moved its focus from being a desktop application to being a web application.
It is finally time to move off of NetBeans and to move off of any Java GUI application. I say this with a heavy heart as I have enjoyed and benefited from both over very many years. RIP.
Aside: If you are interested in large scale, pluggable, user interface design then do read everything you can about the NetBeans platform. It is remarkably well designed.