@jmcguire: Sorry to hear of your frustration regarding Bixby on your Galaxy S9. It isn't possible to remove it completely, however there are ways to reduce its 'presence' on the phone. With this in mind please open Bixby > Tap the 3 dots in the top right > Settings > Voice Response > Hands-free Only > Automatic Listening > Never > Voice Wake-Up > Wake with "Hi Bixby" > Off > Use While Phone Locked > Off.
Then, go to Settings > Advanced features > Bixby Routines > off > Bixby Key > Double press to open Bixby. Hope this helps.