I'm not entirely clear what you're trying to say, but, my understanding is that they simply put lots of copies of files in lots of places like games have done for a long time, in the hopes it would lower seek times on HDDs for those players who use them.

They realised, after a lot of players asking, that it wasn't necessary, and probably had less of an impact than they thought.

They removed the duplicates, and drastically cut the install size. I updated last night, and the update alone was larger than the entire game after this deduplication run, so I'll be opting in to the Beta ASAP.

It's been almost a decade since I ran spinning rust in a desktop, and while I admire their efforts to support shitty hardware, who's playing this on a machine good enough to play but can't afford £60 for a basic SSD for their game storage?