I don't know how often people get hacked, I can speak for myself only. I've been hacked once few years ago. First, my Bitcointalk account got hacked, but I was able to get it back later with help of admin. Later, they hacked my Bittrex account, but fortunately weren't able to withdraw funds. There was SMS 2FA on withdrawals enabled.
I still don't know where exactly I made mistake, but I believe that my email got compromised first. Back then I thought that I'm not stupid and it won't happen for me, I didn't followed even basic things to protect my accounts and crypto. But it will happen for you if will be not careful enough. These tips to protect your accounts aren't made without reason. So, things like 2FA, strong passwords and other things is must have.
I believe that there are many more who have become victims and have not publicly admitted it, as opposed to those who publicly seek help online or report it to the police. The reason for this is very simple, it is not easy to admit that you have become a victim of fraud, especially if it happened in a very naive way that could have been easily prevented.
Yeah, it's not that easy to admit in public that you made mistake and got hacked. Some people don't want to say that because they are afraid to look stupid. Probably I also wouldn't admit if would be hacked in stupid way, like clicking phishing link in email or something similar.