The Google Home Hub adds a smart screen to your smart home. But if you're going to buy a Pixel 3 or 3 XL, you might want to just grab the Pixel Stand instead - that's Google's official wireless charger. The Pixel 3 and 3 XL have a custom UI for the Pixel Stand Only for the Always On screen, though It can push out 10W of power, so it's not the fastest. But think of it this way, it's as fast as the wired charger of the Pixel 2 generation (which was capped at 10.5W). And it has no problems charging the phone inside a case. However, it's the software features that make this stand...
Source: https://www.gsmarena.com/pixel_stand_handson_doing_what_home_hub_does_with_your_pixel_3-news-33665.php