Google Assistant, not Google Home. A dedicated device is not required. You can use your phone for example to operate GA. Actually there is already the ability from Hubitat to command Google Assistant to execute a command without even having a GH device. I think Google will eventually provide equivalent capability under Works with GA as they did before with the Nest developer program. They would be really stupid not to. Let's see, but no reason at this time to jump in my opinion.
Google Assistant isn't a device. A Google Home Hub is a device that you buy that runs Google Assistant. Google Assistant is software. Nothing to buy. You can download it for free on your phone!