Do other databases have read backup similar to Cosmos. Is this similar to read replica as what is available in AWS?
You can have backups enabled in Azure SQL, and in fact most, if not all, Azure database services offer backups as well. Cosmos DB is unique in the way that it enables global replication of data to your selected regions. I am not 100% familiar with the AWS offering, but would expect database backups to be generally available as well.
I hope this helps.