My MacBook Pro was 128 GB of memory is so desperate to fill it up that it gives the applications insane amounts of memory. That only took around 30 GB of memory, so the Mac also loaded the entire file system to the memory which takes around 80 GB. The whole system is super fast because it doesn’t have to read the files from a slow SSD, but from a fast memory.
It’s just a matter of how you look at it. The empty memory = wasted memory.