From what I understand 2nd law of thermodynamics is just saying that information cannot be destroyed, ok got it. When a massive star collapses under it's own weight, it turns into a black hole and all those physical information of the original star simply vanished into oblivion until quantum mechanics come into the rescue by suggesting black hole has a temperature! So the entropy of black hole is related to it's surface area and it should be decreasing over time, now I'm super confused why bother giving black hole entropy to have it blatantly violates the 2nd law of thermodynamics which also saying entropy must not decrease?
The second law of thermodynamics actually requires black holes to have entropy, otherwise you could reduce $S$ by throwing mass into one.
Hawking radiation may shrink a black hole, but the radiation has entropy of its own, so $S$ still isn't reduced. Indeed, if you throw something into a black hole, then wait for Hawking radiation emission to reduce the black hole's mass to its original value, the law predicts the outgoing radiation will have at least as much entropy as the object you destroyed.
So what the law really tells us is blackbody radiation has an especially high entropy for a given mass-energy.