Honestly, I haven't wondered about it until this question came up, I just prefer to do what I can without bothering if it's appreciated or not. One thing I've learned about life is, people need people at every point in life so even if there are people who care about you only, they could be that caring because of you and what you can do.
Life is uncertain and full of drama, it's why we have people who once cared so much and the next time, they are against us in everything. Personally, I've not had to experience such from anyone but I do know I've had people who were so close to me sometime ago but things changed and they are more like strangers from a distance.

For sure, I know a lot of people who care about me for many reasons and a few that care about me because it's me. My family is one of them, and I mean my dad, mum and siblings. I also have an aunt I would say cares for everybody around her, including myself whenever I'm around her and it's beautiful to know I have these people.
I've had different experiences in life, so many were good and I've also had bad ones too, with people. But I honestly don't think I can decide which to think, if people care about me or what I can do for them. I believe it should be more of what I think about the things I do for people and how I go about it than what they think about me.
People will always think and do what they want, you can't control that. You can only control and decide what you think and that is where you don't care about what people are coming to you for, worrying if they truly care about you. The only true love and care I know that exist is the one I have from God who have proven His love for me.
But I keep a positive mindset that people who understand what it means to truly care with God as their role model, will find me just as I will find people who are in need of love and care that I can give. People care more about what people can do for them but true care is possible too and we are to be the people who give the true care.
Image used is AI generated.
Let me paraphrase an incident I read in a book. The author says "I rescued a snake from a dangerous situation. And in return, it bit me. It did what its nature was 😄"
The thing us that people only give back what they have inside them. It is often disappointing to expect the returns in our favour. There are good people and bad too. Nevertheless, our character is ours and we are supposed to elevate it.
About relationships particularly, I would say that, no matter how loving and caring the companion may be, relationships build on reciprocity. Without giving love and care back, it is injustified to keep on expecting the same care always
I like to think that the only part we actually have control over is the part where we choose the kind of person we want to be. We can spend so much energy trying to analyze people’s intentions, whether they love us for who we are or because of what we provide, that we forget that relationships are rarely that simple. Sometimes people genuinely care about us and value what we bring into their lives. Those things don’t necessarily cancel each other out.
The part about people becoming strangers after once being close is very relatable. Not every relationship ends because someone did something terrible because people simply grow in different directions, and suddenly someone who once knew everything about you becomes someone you only recognize from a distance. And yeah, your conclusion is the healthiest part, instead of becoming cynical because you’ve experienced conditional care, continue being someone who gives genuine care. We can’t control what people do with our kindness, but we can control the kind of person we become because of our experiences.