Why did she let me go after three months?

i was in a talking stage with another girl for three months. within that three months, i had plenty of time to ask her to officially be my girlfriend and in that three months of talking, my friends and her friends even said that we were basically dating already based off of how we acted. she went on a trip for five days and when she came back she ended things with me. she said that i deserved better than her and also for a bit of context, her best friend and i hate each other so that was a big issue for her as well. i consistently asked if i was worth her time because of the conflict between her best friend and myself. she always insisted it was okay and that she'd figure it out. i'd reach out multiple times to tell her i was there for her if she ever needed to talk about it. i was sad and upset when she ended things with me (as one would be). a few weeks later i found out she had a boyfriend. and more weeks later i found out she started dating her current boyfriend the same day she ended things with me. and she had met her boyfriend on her 5 day trip. when i found all of this out, it hurt even more. it's now been more than 8 months since she ended things with me but i still miss her so much. about a month ago, after roughly 7 months of no contact, she sent me a snap. we started doing streaks again, but nothing more. and it's made me miss her more than ever.