Why do the resistant and senior people still block me?

You have made progress. You can move some things now. And still, the same resistant colleague says no, and the same senior person finds a reason to wait. This feels like an injustice — as if your growth earned you a right that others are refusing to honor. It did not earn you that right. No amount of your own change obligates another person to trust you, promote you, or stop protecting their ground. They are not blocking your growth. They are protecting something — their risk, their reputation, their own uncertainty — and your growth has not yet touched that thing. So the work left is not to prove you have changed. It is to find out, person by person, what each blocker actually needs before they will move — and to decide whether you are willing to give it.