"I love you" means like you actually care and have so much love and affection for that person. It's used to express affectionate approval for someone. Sometimes, it can mean something else, more of like in a deeper feeling... Like for instance, NF, a rapper, he makes a song that is called If You Want Love, and explains what you have to do just to earn that actual true love.... Love can also mean spending the rest of your life with that person...
Hope this helps you!!! :)
