The list of smart home devices will always be growing. I am not quite sure if we will ever be able to stay on top of that. Google seems to be making an attempt. Google has published a list of supported smart home devices.
At my day job, I help handle an online help center. Looking at the long list that Google has published, complete with link to their websites, I can imagine the kind of effort that the team has put together. It will be even more difficult to maintain this list. Unless they have set up a system for the providers to submit changes directly!.
The list has an drop down to filter by the provider, and also a search field. This is also a good move. So, if you are looking for an official list of Google Home supported smart devices, here it is.
While you are there, say thank you to whoever created that long list!