This only works if you are in charge of the timelines or have a manager who values quality over quantity
By that time, you will have probably left the company and someone with less care about code quality will come and undo your work.
Also, like security, it is hard to show to a manager data and graphs showing how much we are saving
And also if you're not in a bad starting position: you could have a system that is very hard and slow to work with, meaning that you can't feasibly introduce much easy to use functionality, especially if the domain logic is tightly coupled.