The “compact” list always includes some languages I don’t use (e.g., Russian and Romanian), but never includes languages I don’t speak but use (e.g., Japanese, Hebrew). Before I noticed a search box in the menu I had to spend like a minute scrolling through the list of languages every time I need to find Japanese (it’s way down there in the Asia section), which is very annoying. For some reason it knows to “suggest” Korean (which I do use, very rarely, like Hebrew) but never Japanese or Hebrew.
If this is some kind of machine learning I suggest that it be be nuked and replaced with a user preference; machine learning often does not actually work. (To be honest the non-compact list is a lot more user-friendly.)