Go on the Galaxy Store & type in 'Remap Bixby key' there should be an app with a microphone on it. Install that then go to your settings for the Bixby key. Apply the 2 press for Bixby and add the app for the Bixby key. It will bring up Google assistant instead of Bixby.
Agreed I have found no use for Bixby nor have I found anyone who does. The choice to use an app should be an easy choice/selection and not accompanied by dire warnings. Even those that can be disabled, continue to show high battery use. Between that and the planned obsolescence of the sealed battery are reasons to consider other options.