A lot of time I think not reading cues, cat fishing, comes down to miscommunication in a relationship, friendship, or association. Not everyone is going to be there long term. Some folks are meant to be there for a season. Just depends on how you are growing honestly.
Breakups stem from something typically, rare to be out the blue, and any relationship is going to take a lot of work.
No one is immune to miscommunication in any relationship. Did you ask the person upfront pointed questions right away? Did you give yourself time to observe if someone is genuine or has an agenda? Do you have an agenda and get blinded by obvious clues? Did you have different expectations and try to force change vice versa?