Notable that saying "I love you" directly to somebody is considered a very Western/American thing in cultures outside of the West.
that's less that other
cultures languages
don't say it, and more that, most
cultures languages, have different words for familial love, romantic love, friendship, liking something, etc.
For instance, in hebrew, ahavah (אהבה), is the word for romantic/intimate/familial love, and chesed (חסד), is the word for...I suppose the best way to translate it would be 'loving kindness'.
For another example, in Greek, there is, Agapê (love, charity), Philia (friendship, love), and Storgê (natural affection).
The fact that the English language rolls all these ideas and concepts into one word, 'love' is really something unique to the English language.