There are addresses with large amounts that are not active for several years. How many inactive addresses with a small amount is unknown, probably a lot. Therefore, there is hope that bitcoin is not completely under control.
I'm afraid to imagine the number of wallets with lost access codes, these digital currencies cannot be returned to the cryptocurrency market.
Yes, it is quite possible that there may be a lot of lost bitcoins. In this case, it is difficult to understand how many coins are in circulation. And to what extent it can be controlled.
I have heard that from 25% to 40% of all existing Bitcoins are lost and out of circulation. Different source gives different information. The number evaluate from 25% to 40%. But this is a very big sum.