If your not really satisfied with Bixby, Samsung's own Artificial Assistant, then you might be able to get Google Assistant for Galaxy Watch running on your Samsung Wearable. Specifically the Galaxy Watch, Gear Sport, or Gear S3. Cybernetic87, an XDA Developer, is currently developing the solution. It is called GAssist.net and it is currently in Pre-Alpha stage.
Google Assistant will be available on your wrist for any Samsung smartwatch device that runs Tizen 4.0+ and has a microphone and loudspeaker. On launch, the dev is hoping to have two versions of the App, one FREE and also a Premium version. Do not worry, the paid for version shouldn't cost more than $2, which seems a reasonable price to me. If your smartwatch does not have a loudspeaker, then do not worry, as a separate all will also be developed. This is for wearables like the Galaxy Watch Active, requiring text output.
Ultimately the Google Assistant for Galaxy Watch App will be available from the Samsung Galaxy Store. Many of our readers prefer Google Assistant, but it is only available on Wear OS wearables at the moment. We have already seen another App, voice in a can, that brings the Amazon Alexa Assistant to your Samsung smartwatch.
GAssist.net incorporates real-time voice recognition text display, ability to stop assistant talk with the press "Listen" again. There have been lots of other performance updates and library changes since its first inception. One little caveat is that the watch has to be connected to the phone in order for it to work.
No download is available at the moment, but the dev welcomes Interested users to join his closed Beta. If you want to participate then you need to provide your Watch Model, Tizen Version, Phone Model, and Android Version. The dev is looking for experienced people with some tech knowledge who can send logs and screenshots. This will all help in bug squashing/debugging the app. You can join by message him directly here.