>I'd honestly prefer if it were just some crusty old Java monolith where all the objects are stateful, and have setters for every field, and all that good^H^H^H^H stuff. Because, while that kind of statefulness may not be well-isolated, it is navigable.

Am I getting this right? Your issue is a lot of hidden, opaque access to external state, so you think adding even more internal state on top would be a remedy because the stuff you add on top would be navigable?