After several months, I noticed a big difference between the question-and-answer websites that allow and those that prohibit ChatGPT. I used to use a website, which used to be good because it enabled me to communicate more easily (as English is my second language). I asked a question about C# on that websites recently. However, after I posted my question, the only one who answered my question was using ChatGPT. What surprised me even more was the administrator did not ban him, while the answer is completely wrong. Compare Stack Overflow with that website, I can get better answers in a shorter amount of time on Stack Overflow.
What's more, people on that website, who tried to help people, start to not willing to answer questions. They write an answer for a long time for a question, but they can get less reward than those who use ChatGPT.
