For my opinion, Azure SQL DB Serverless is useful in development and testing environments
This makes it possible to have a database at a lower cost if you do not implement an automatic process to create test database that includes test data for your development teams.
Just take into account the restart time of the database in the tests.
Ideally, you can create on-demand test databases with up-to-date data. But this requires a real strategy of automatic deployment that also has a cost.