For comparison it depends on what you are actually doing. You can even do hybrid hosting using VMWare in both Google and AWS that interfaces with the wider cloud offerings.
In terms of major differences AWS would win on just having more capacity than Azure and Google so when you really do need to scale you do not have to worry about error messages popping up telling you that you are not able to start instances. There is also the wider services and newer services being released that happens more frequently than the other platforms. Google does have some serious K8s support and data science tech that is pretty amazing and easier to use (web UI wise). Though AWS has similar tech but easier to use as a developer or engineer. Either way both are wonderful platforms and can meet your needs if you build your service correctly.
Although Google Cloud Platform outperforms AWS in terms of price and flexibility, AWS outperforms Google Cloud Platform in terms of global scope, with considerably more data centers available around the world. Furthermore, Amazon Web Services (AWS) is building new data centers at a faster pace than Google.
