In Japan, there are 3 ways to say “I love you”:
You say “Daisuki (大好き)” for the friends and person you like,
you say “Aishiteru (愛してる)” for a more serious relationship,
and you say “Koishiteru ( 恋してる)” to the person you want to spend the rest of your life with.
And they follow this rule. They preserve the meaning of ‘I love you’ and never lose its essence unlike us.