This was true for me as well until I used DBeaver (a universal database browser tool) I only realized it was java after I tried connecting to a really old server that needed me to change my ssl settings in the JRE. The user interface feels fairly snappy. DBeaver is a really fantastic tool and I don't see myself changing any time soon. It even supports making its own SSH tunnels to your database server using your local ssh agent.

I can attest that AWT and Swing were hot garbage 20 years ago, though. The cross-platform aspect worked great, but the algorithms weren't worth making cross-platform to begin with. It was basically a giant GUI ecosystem written by people with no understanding of how to implement graphics efficiently. My favorite was how they bragged about their "lightweight" visual components that don't require OS-level window objects. Except, OS window objects are part of an algorithm that tracks exposure regions and repaints it efficiently without needing to redraw the whole screen. Swing took the approach of repainting the entire application window in a back-buffer on every visual change and then copying that up to the entire application window area, even for things as small as tooltip pop-ups or menus.

I haven't checked which GUI framework DBeaver is using. I suppose it's possible that it is Swing and my workstation is just so fast these days that the inefficiency doesn't matter.