3rd party "Works with google home" stuff will often stop getting updated causing more and more functionality to break over time. Admittedly this is an issue you can avoid by entirely buying the products actually made by Google, or at least carefully selecting third parties, but a huge amount of smarthome stuff is going to be rendered non-functional because of this sort of thing.

I do think the 1st party Google Home stuff is supported well enough, and I don't think any of Google's competitors in the smarthome space are really offering anything that's obviously more compelling. I mostly recommend people either go with big brands or something that can be flashed with tasmota, pick your poison.