It's worth actually being specific about what differentiates a junior engineer from a senior engineer. There's two things: communication and architecture. the combination of these two makes you a better problem solver. talking to other people helps you figure out your blindspots and forces you to reduce complex ideas down to their most essential parts. the loop of solving a problem and then seeing how well the solution worked gives you an instinct for what works and what doesn't work for any given problem. So how do agents make you better at these two things?
If you are better at explaining what you want, you can get the agents to do what you want a lot better. So you'd end up being more productive. I've seen junior developers that were pretty good problem solvers improve their ability to communicate technical ideas after using agents.
Senior engineers develop instincts for issues down the road. So when they begin any project, they'll take this into account and work by thinking through this. They can get the agents to build towards a clean architecture from the get go such that issues are easily traceable and debuggable. Junior developers get better at architecture by using agents because they can quickly churn through candidate solutions. this helps them more rapidly learn the strengths and weaknesses of different architectures.