A friend of mine has this joke he likes to tell about having Siri start a conversation with Alexa, and that's how you get cylons. Samsung had a virtual assistant for years called S Voice, and it was pretty good, but it was replaced by Bixby a few years ago. People I've talked to are divided into two camps when it comes to Bixby; they either love it, or they've never used it (him?). When Galaxy phones first came with a dedicated Bixby button, people immediately wanted to remap it to Google because that was the virtual assistant they were most familiar with. The cool thing about the S10+ is you can have both Bixby and Google respond to your voice without touching the button, and even if the screen is off and locked. Just say, "OK Google" or "Hi Bixby". Just don't say "Hi Bixby" when Google assistant is open.
To set up two assistants, open Bibxy, then click on the three dots in the top-right corner.
You should see this:
Now, click on the settings for the Bixby Key.
Finally, set Bixby to open after double clicking the key instead of the default single press (see below). Finally, the two virtual assistants can live in peace, although I do actually have Alexa on this as well...