And even if you manage to convince your manager to consider you for the promotion/transfer often they'll ask you to start doing the new job on the side for a bi

And even if you manage to convince your manager to consider you for the promotion/transfer often they'll ask you to start doing the new job on the side for a bit to prove yourself. Now, how good are you going to be at something new that you are doing part time with nobody taking you seriously and supporting you? It's much easier to get the title first and grow into the job afterwards.