If you are learning the core of Bitcoin or what Bitcoin is, people must know by the beginning, there will be only 21 million Bitcoin will be generated.
You got a point that for that Bitcoin who already lost like wallets or private keys already lost and impossible to access anymore.
What's my take here is somehow they are "burned" which will help the supply of Bitcoin will decrease and by that, I believe it will also a good help somehow that it will increase the price of Bitcoin.