Why would someone become an enemy to another in the forum? I am wondering why they would keep enemies between each other when the forum allows you to hide your identity under your username. Anyone who will think of such an evil act is a wicked soul. But your advice is true, we do not know if anyone is jealous of you to the extent of sending their BTC to your address, and that's why it's good we ensure the security of our exchange address.
No one knows what's in someone's heart, even though we don't know each other because our identities are hidden, but there are always bad people who want to harm us, maybe many factors such as envy and so on. That's why Op's advice is very important to always keep the exchange address secret, especially if you post it publicly. On the other hand, that's the biggest risk of storing assets on the exchange besides not being able to control it yourself, all of our assets can be frozen by them if someone wants to harm us by sending btc using a mixer to our exchange address.
One annoying thing about the blockchain is that it is transparent. Anyone who sends funds into it cannot be hidden. People can see your balance and transactions and track which user sent it.
A transparent blockchain is not always annoying, in fact, with a transparent blockchain there are many benefits. With this blockchain transparency, it can increase the trust of many people. With blockchain transparency, it will also be very useful for audit purposes and with transparency, its truth can also be guaranteed, and there are many more advantages of blockchain transparency.