Reitse Eskens keeps things basic:
When you look at the documentation, the basic tier has low CPU (at max less than one), 1 to 4 IOPS per DTU (translating to 5-20 IOPS in total), a latency of 5ms read and 10 ms write and a maximum of 7 days backup retention. Even though it’s advertised as a production database, I wouldn’t store essential data there. However, I can use it for metadata storage in a Data Factory or Synapse Analytics environment.
About the IOPS, one IOP is a read of a disk cluster, usually 4 Kb. In this case, this means that the database is capable of reading 20 to 80 Kb of data per second.
When they say Basic, they aren’t kidding.