Today, we're near the 19.5 million mark, and what OP said is true and it's estimated that millions of Bitcoins have been lost by people throwing away their wallets or forgetting their private keys. But behind all this maybe users need to look for this type of wallet which is the safest where the user does not need to open his private key to the network and Hopefully, We now understand what Bitcoin is and why everyone in this world is going crazy for it.