It’s probably worth mentioning that an “arranged marriage” can mean anything from when two families agree to marry off their children without their children’s consent, to when families play match-maker and set their children up on dates but their children get the final say.
In India, for example, you get both, with the former being more common in conservative, rural areas and the latter more common in urban and middle-class areas. So it’s not a one-size-fits-all situation.
As to why it persists? Practicality, I suppose. If you want to get married, it helps if you filter out all the people who aren’t serious about settling down. Plus it’s not like love marriages have a superb success rate, given how common divorce is nowadays.