The problem isn't DRY, the problem is "helpers". Helpers are an anti-pattern, they don't fit in your architecture, they have no mental model, they're difficult (impossible) to name and organize, and they're extremely resistant to refactoring. Effectively they're spaghetti code.

The example I always come back to is auth. If you're doing the same thing like "parse a cookie header, get the session, make a DB connection, look up the session info, etc. etc.", consider how you could architect the layers of your application using a mental model that people would find easy to reason about. That might be some OO, middleware, or even a macro, but the point is that it's thought about, designed, engineered, and documented.

The reason helpers are more prevalent than thoughtful architecture is that humans are a lot better at prioritizing the short term "I improved it" fix from factoring into helpers over doing the long term work of architecture. If you want to change this, it starts with cultural values that prioritize long term sustainability.