Scalability and speed are limitless. All of this is abstracted away from the end user so that you can focus on the concrete logic of your use case.
Google makes it easy to understand complex concepts. By reading the documentation, you can easily jump-start developing with any of their solutions. The UI also makes it a breeze to navigate through your organization and the products used.
Cloud Composer for Airflow and Dataflow for Apache Beam are some of the fully managed data products. Forget about all the provisioning and dealing with boilerplate and start implementing immediately with those great OSS solutions.
Google has been investing massively in its training platforms via custom courses on skill boosting, Codelabs, and a variety of courses offered on third-party platforms (Coursera, Cloud Guru, etc.). Learning has never been easier, and the high level of pedagogy makes it accessible to anyone.
The community is huge and keeps on increasing. You will find many threads on StackOverflow in case you face an issue. And if you have Support access for your Google Cloud organization, you can access Google engineers who will tackle your bugs in a matter of hours.
Chances are that if you start from scratch, there is already some quickstart terraform module or template repository that you can use to start with best practices from Google engineers and the community.