Note: I do not work for Azure

While I prefer GCP over Azure, despite being Azure Architect -

1. Cosmos DB statement is not correct -

It allows autoscale, same way as AWS DynamoDB,

https://docs.microsoft.com/en-us/azure/cosmos-db/how-to-provision-autoscale-throughput?tabs=api-async

2. Azure automatically manages partitions, while you still fine tune different aspects https://docs.microsoft.com/en-us/azure/cosmos-db/partitioning-overview