Lots of people are afraid of taking imperfect opportunities because they might get pigeonholed. They worry that if they start in a position different than their ideal they will get stuck there and have to spend years doing something they don’t want to do.
This fear is based on a fundamental misunderstanding of work. It takes on the idea that opportunities need to be given to you and not earned. That you have no power to change your role once you accept a job offer.
The reality is that no matter where you start and what you start doing, you can work in the direction of your goals. All you need to do is think creatively about how you can create value for your employers using the new skills you are learning.
The fear of getting stuck is not an external fear based on the company, it is an internal fear from the lack of confidence in your ability to actually follow through with your goals.