Why does she insist on doing this?

My girlfriend broke up with me earlier this week. After I left this was the last portion of what she texted me. :I hope you don't disappear on me but I understand how hard it is. I can't ask you to stay and leave at the same time. I will always love you to the bottom of my heart. All I want is for us both to be happy and I truly feel like in the future we can find each other. We can figure it out." I'm honestly at a loss for words. She seems to just want to keep me around because I am a safe space she wants to retreat to. If she feels that then why couldn't we be happy together now? What does she need to figure out?
Why does she insist on doing this?
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