These observations speaks volumes as to how testing is often done badly. It's a bit of a generalisation, but if you move your reads/writes to the periphery, the

These observations speaks volumes as to how testing is often done badly. It's a bit of a generalisation, but if you move your reads/writes to the periphery, the core tends to be pure functions that are easy to unit test without side-effects. If you don't move your reads/writes to the periphery, everything becomes an integration test, with the accompanying brittleness, lack of performance, and resistance to change. TL; DR: Stop designing/implementing things such that you have to mock everything; DI is just a tool, and as such it is used for both good and evil.