Hmmmm...I care about you sounds more personal and meaningful. I care for you seems like there May be a condition attached or something. Idk. It’s like someone saying I have love for you. Ok, so if you truly have love for me than why not just say I love you. Almost like the use of the word for is a roundabout way of having to say something that you don’t quite mean. Disclaimer: These are just MY feelings. That doesn’t mean someone’s t who does use the word for feels the same way.