This is a hill I will die upon: The people who don't deserve rewrites ask for them, early and often. The people who deserve a rewrite rarely mention them, and in fact they likely already have done it, bit by bit as a sibling comment mentioned by way of example. I will say that I've often surprised myself with features I never would have hoped for on the refactoring road. Things that would have been entire Epics become six weeks of work, sometimes less.
Refactoring is the Ship of Theseus scenario. You replace the ship bit by bit, until it's both a new ship and the same ship. Yes, it's a titanic pain in the ass, but it's also atonement for your past bad decisions. Which are heavily populated with cut corners you will be able to spot the next time.
All worthwhile learning is effortful, and greenfield is the lowest effort path to anything. You don't learn much from greenfield except why greenfield is not a panacea.