There is a HUGE monetary and time benefit to having developers spin up docker/vagrant environments to run integration/etc tests on their laptops before it hits CI/CD systems so I completely disagree. People thought we'd offload developer computing to the "cloud" 5 years ago. It's not coming soon, I doubt it's coming in the next 5-10 years if you're making applications that now rely on microservices, kubernetes, etc.

AWS charges by the hour, GCP charges in 1 minute increments after the first 10 minutes. That all is extremely costly if you have a number of developers sending all of their tests through those systems.