Google Cloud has MySQL for RDS. Agree that its lacks Oracle, MSSQL and Postgres. You can use managed Postgres by Enterprise if you like. If you are startup and running Oracle in AWS / Google Cloud, that's probably not a wise choice (You don't get the benefits Oracle, which is performance in AWS / Google Cloud). A startup using MSSQL in cloud? May for a niche purpose. If you are a big company with lots of legacy apps built with Oracle / Postgres / MSSQL, AWS makes more sense in short run.
