Hexagonal architettures combined with a command processing pipeline help in defining test boundaries and entry points. Those entry points are your public interfaces, everything beneath shouldn't need any test. The entirety of the core application behaviour is testable in isolation by design. You basically end up writing mini acceptance tests for your domain logic.

I think that's a preferable approach for complex systems, the "redundant tests" issue is not a problem and end to end tests are reduced to just a few proving everything is hooked up.