This is simply not true, and has never been true anywhere I've worked. We can do everything with a much better UX in about 2,000 to 3,000 lines of code, instead of ~25,000 (and almost 2,000 dependencies).
It's a boring tedious "true-ism" that keeps getting pounded. I don't really know what else to say, but it's simply just not true.
What is the longest you have ever worked on a single piece of software? If you are in some sort of consultancy or jump jobs every 2-3 years it most definitely won't be true. You stay with a product for 5+ years it is bound to happen unless your dev shop is like 10 people. If you think this is not true AND have spent 5+ years with the same piece of software you are an outlier...
It's a boring tedious "true-ism" that keeps getting pounded. I don't really know what else to say, but it's simply just not true.