The difference is that lowering the estimate for a given amount of work doesn't actually get it done quicker - it just means you have a more unrealistic understanding of the timelines.
You can absolutely work to find other creative solutions to the same problems, or understand what scope is acceptable to cut to meet some goal. That's very different from "I want you to do exactly the same work but just do it faster".
If your stories are so well defined the dev doesn't have any decisions to make in the process of coding, then they're more of a glorified type writer than a dev.
There's plenty of decisions devs make that impact how quickly they deliver a solution.
You can absolutely work to find other creative solutions to the same problems, or understand what scope is acceptable to cut to meet some goal. That's very different from "I want you to do exactly the same work but just do it faster".