I've seen many questions and tutorials about how to map JPA entities to SQL views. But none of them explained how you could create SQL views using JPA. I'm wondering whether this is possible or not. In worst case I have to create all views manually, but then I don't know a reason to use JPA anymore.
It is not possible to create automatically a view directly with JPA, including Hibernate, from the mapping metadata.
You can, however, use the persistence.xml property "javax.persistence.schema-generation.create-source", combined with "javax.persistence.schema-generation.create-script-source", to allow the persistence provider to execute a given script to drop the created mapped table of the "view entity" and create its correspondent view. The view entity must be mapped as described in Does JPA support mapping to sql views?. This method requires the database administrator to create the view manually, as you wrote. Please check chapter 9.4 of JSR 388 (https://jcp.org/en/jsr/detail?id=338) for further information.
Sure, it's a matter of taste or opinion if the lack of this feature makes JPA/Hibernate not interesting for your use case.