Although the current version still has to add support for a few widely used languages, Samsung Bixby 2.0 is apparently on its way and the updated virtual assistant is expected to come with improved third-party integration and support for other devices than smartphones.
https://www.notebookcheck.net/Samsung-Bixby-2-0-might-arrive-this-week.258338.0.html
The same as with payments, its not supported in every country/language, also button can have more meaningful usage as to show health app, navi and so on based no how long you press. While it got just one for many useless function, as it kills point of voice commands.