You can do some stuff on cloud; for example, for a few minor projects where we needed to make some web pages, we used GCP. However, it wasn't well integrated with internal, it was effectively just a web site like any other.

I believe there had been multiple waves of attempting to get people to move to cloud, but at the time, there was no coherent strategy to move large parts of the tech stack to cloud. Unfortunately with any sufficiently complex production service that runs in borg, untangling the web of dependencies is usually too hard.

Other things work great in the cloud; if I was a Google Researcher working on public data and publishing papers, I'd intentionally use Google Cloud (with access to VMs, CPUs, and GPUs, but not any internal data like the web page crawls) with Jax, Keras, TF, etc.