Alright, so we’ve already established that there are no guarantees…for many things in life…let alone marriage.
I wouldn’t say “no one”. There are some (or a few) cases of blind marrying. Or where the guy/girl talk n meet very few times.
Dating doesn’t necessarily ensure that you will know your partner well…but going into marriage without getting to interact with your partner (at least barely) is a BIGGER risk. And there are cases…where girl lives on one continent…guy on another continent…only photographs are seen…and nikkah over phone. And such a marriage COULD turn out to be successful…more so than one where dating was involved. But…it’s a bigger risk…a bigger gamble.