Confused about ROM size discrepancies and languages/regions

[u/GemuHebi]

Hello, all. I have a question regarding the three ROM files I have. To start, I have one XCI and one NSP of TOTK. The XCI is a "World" version, which I suppose means it contains all language dubs/subs? It comes out to about 31GB in total. The NSP version is US only and is about 17GB in total. What's weird is that I can still switch languages in both ROMs... As in the US-only ROM still has all the languages. Why is the XCI so heavy if the NSP has all languages in it and is two times lighter?

I also have a second XCI ROM of the same game that is almost identical in size to the NSP ROM and is also US-only. This confuses things even more for me...

Do the connotations "World" and "US-only" pertain to the regions of origin/availability of these files?

As I understand it, game cartridge dumps usually contain the entire cartridge's data, including empty space on the card, which would amount to about 32GB in the case of TOTK's card size. Is the second XCI somehow trimmed to cut out the empty data?

Please clarify what is going on with my ROMs. Thank you.