Latest software (using v10.3), better performance (nvme SSDs), better backups (point in time, instant cloning), better features (more extensions, cross-region replication even across different clouds), better flexibility (migrate master across different clouds), better monitoring (logs and datadog metrics export), and more focused support with a smaller team.
Yes, I know. This thread is about managed database services, specifically about Aiven vs cloud-direct. Aiven still runs VMs on AWS or GCP but offers nvme disks while neither RDS nor CloudSQL have that available.
For our needs, yes. They run on cloud VMs so there will be a markup but their startup-4 and higher plans on GCP use local NVME SSDs so we get much better performance for the price.
We also make use of cross-regional replicas and are looking at doing it across clouds so if you want that then there isn't any other option other than doing it yourself. It's more of the complexity of this deployment rather than raw db size for us so if you have several TBs then maybe it's not the best fit.