The inconsistency with Google Home’s/Assistant’s behavior is frustrating, but I get that from Alexa, too (though, admittedly, I’m newer to Alexa and haven’t used that as much). What’s weird to me about third-party cameras is that I’ve been able to stream live views of Wyze and Arlo cameras in the Google Home app for quite some time now, but that hasn’t worked with some other cameras even though Google Assistant will correctly respond to a voice command and stream those other cameras on a Home Hub or other devices like a Google TV or Chromecast HD. Just recently I enabled the Public Preview because I want to play around with scripting in Google Home for Web, and since then I can sometimes see some of these other third-party cameras streaming in the Google Home app on my phone.
I also seem to get more reliable weather information from Google Assistant. If I ask Alexa about wind speed, it responds with other weather stuff but specifically excludes that. 
Sometimes I think it’s funny how frustrated we can get because our expectations have changed so quickly. None of this stuff was possible a few years ago, but now we have all of these connected gadgets that allow us to control our environment by talking to computers, which is amazing! (Sometimes I think it’s like living in Star Trek.) Then when something doesn’t work as we expect, the 
come out (for me, anyway). It’s kinda silly when I step back and take a look at it, but at the same time we do want the stuff to work as expected.
There is no perfect system, and I don’t know what the balance is.