Some people do not compare every symbol of address and watch for example only last 4 symbols and can send funds to scammer's address.
That's simply because people are often in a hurry while at it, during transactions. It's good to suspend everything one is doing during transaction. That's what I do. I'm never in a haste because I know once a mistake happens it's goodbye to my funds. I do take my time to check the first four/five letters of any copied wallet address I'm sending or withdrawing to. I do same for the middle and last four/five letters too. That's if the funds involved aren't much. If I'm doing a heavy transfer, I take my time to run a complete check from the first letter to the last before hitting the send or withdrawal tab. I'm conservative like that and I haven't regretted any bit of being conservative.
You don't even have to do that. Unless hackers have full control of your computer or phone, it's enough to copy paste address from the exchange, if you're sending to exchange. If it's your address, also copy paste, or use address book in your wallet. This kind of attack is effective only against people who don't take security seriously at all.