I have been through several full rewrites of major money makers. It’s almost always a really bad idea. Almost being the key word.

Beyond second system syndrome, you really have no idea what your users actually like about your product vs your competitors. You’re too close to the product.

A rewrite that breaks users muscle memory and frustrates them is the perfect time for a jump to a competitor.

You are basically always better off mutating over time at a much more tolerable rate.