I worked on an app that was using Java Web Start still, as of January 2023. It was a problem, because JWS was not included in the parts of Java that were open-sourced, and was not available as part of recent OpenJDK versions of Java. Some open source JWS implementations exist, when I left that job though, the situation had still not been resolved in terms of finding a JWS replacement. It was imperative that we get off Oracle Java because of their expensive upcoming licensing changes. I wonder what ever happened..........