Why do most BTC price prediction models fail this year?

I saw a saying:

Because the user purchased BTC on the centralized exchange but did not withdraw the money.

This results in that the part of BTC that has not been withdrawn is not actually purchased, but only a number displayed by the exchange to the user.

According to estimates from thunderstorm data from a well-known exchange, the number of BTC that has not been withdrawn from one exchange alone is equivalent to increasing the total supply of BTC by 25%. This is only data from one exchange.

Just imagine, if all exchange users withdraw their BTC, how much will the real circulation of BTC be reduced? Will the price of BTC remain the same as it is now?