For simple use cases where I mostly just read/write from the database and don't expect any of those issues mentioned in the article (constraint violations or concurrency issues, because the application is quite simple tbh, plus I already have some testcontainers based integration tests for the components that deal with a real db and I reuse them) writing tests with an in-memory db implementation is quite nice - the setup is simple and running the whole test suite is instantaneous (literally something like 1-2s for a couple thousand tests, I don't need any framework for those kind of tests).
And on the other hand if I'm relying on something like an optimistic/pesimisstic lock or a framework feature, I will write a test with the real thing, using test containers. Also have a pretty good coverage with the components that deal with queues and databases specifically with testcontainers. And on top of that just a few e2e flows written using testcontainers as well.