Moreover, if the price of Bitcoin decreases, people's demand will not decrease, rather they will invest in Bitcoin, if the Bitcoin market drops again, then I will definitely join the investment.
Bitcoin price is determined by supply and demand, and the price increases due to the increasing demand from people. Therefore, if the price falls, it means that the demand for Bitcoin is decreasing. So it would be incorrect to say that when prices fall, people's demand will not fall.
I agree that the scenario of bitcoin price dropping to $500 is not going to happen, that sounds very absurd in the current situation. But let's say if that happens, it means the demand for bitcoin has dropped drastically and people tend to dump it. How can the price drop to $500 if demand doesn't decrease?
Price and demand are closely related and reflect each other.
Yep, still don't it happening.
Imagine what would happen to all the other coins on the market too, though, if people and investors don't see BTC, the stronghold of stability, the same way they do...