I think that you can truly love people who are not healthy for you or whose circumstances ,or yours ,are not healthy for either ,and so it just doesn't work out long term.
Personally,a lot of the time it feels much easier to maintain healthy relationships with people I have no feelings for ,exactly because of the fact that I am not attached and I have no expectations or needs or wants from those people that are complicated or demanding. And vice versa.
I think that it is even factual ,where most long term relationships work because people are simply compatible ,not because they necessarily have strong feelings for each other ,but because their personalities and lifestyle and timing etc etc work together.
It's a bit of a touchy subject for me because the only times I have truly loved my partners were both cases in which things didn't work out because of circumstances but it doesn't diminish how I feel or have felt . I could choose someone I am simply compatible with ,certainly. And I may in the future, I do not know. But I am too immature at the moment to do so . I guess ideally everyone wants to be with someone who they are both compatible with and also love. But it doesn't seem probable