First of all, up-to-date official packages are now published to Maven Central as part of the release process, so you can just add it as a dependency as easily as with any other library. Until recently you would have had to either fiddle around with Eclipse's alternative package management system, download it manually or use someone's unofficial Maven artifact. But that's now resolved.

Secondly, if you bundle a Java runtime customized with jlink (as is recommended these days), an SWT application is actually smaller than a Swing application. When you don't use Swing, you can exclude the entire "java.desktop" module, which is slightly larger than the SWT libraries.