It's not all about receiving lots of phishing/spam emails or sms.
Worst case is your name is being used in any criminal act such as swindling or estafa, or simply identity thief. Since most of these leaked information are the one that is needed to apply in different agencies/stores/etc. which include your name, IDs, address, birthday, phone number, etc. These criminal acts can be applying a loan (this is common) in both private and government agencies, use your driver's license info and get road offense (there are incidents like this too), you can be a victim of sms cloning using your info, then getting robbed again, and many more possible cases which will end up destroying your reputation.
It will be too late the time you discover that your name is used and labeled as criminal in the investigation bureau. And this will bring someone's life in misery, possible will end up being in debt. This cost you more than anything than those amount that got hacked from your exchange or casino balance's account.
All I could think about how KYC is very dangerous is that hackers can provide the data for other attackers in a way they can physically rob the victim. This is very possible which could even be happening. Another is the phishing attack which is very common. Another is the selling of the data which can be used in what you are talking about above. But as for these to lead to a case that the innocent person to be seen as a criminal of the offense he did not commit is what I do jot know much about as I haven't heard about such cases before, but better to protect oneself from these kind of attack. But how? Most people are doing KYC. 90% or more people are doing KYC, only few people are not.