Evaluated GCP, and 2 main issues made it hard to consider moving: 1) quickly bumped into project limits just doing some tests, and the fact that you have to wait until billing cycle to reset the counter was quite jarring (I presume there's a way to increase) 2) Better tooling for S3 than Google Cloud Storage - non-technical members of our team need to work with files, and there's many nice third-party tools for s3.
The time I opened a new account on AWS to do some disaster recovery. I had to send Amazon ~ 30 tickets for increasing limits and wait for a week :D