sorry the question seems to be very complicated to understand but i will answer upon how i get the idea.
Bitcoin maybe lost in the air as i have did this in past when i sent in wrong address but that is commonly happens.
what you are pointing if time comes that all of the 21million bitcoin lost like that right?or some of them are owned by death person that no one knows the key of their wallets.
exaggerating obviously but even there is only 1 bitcoin remains still it can be divided into how many Satoshi?meaning there are still in circulation.
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I think you're mistaking 1 BTC for 1 satoshi. Do you also think $1 is $100 because the lowest denomination is 0.01? The fact that a Bitcoin can be split into 100 million different pieces doesn't make its supply endless.
that is what we are all pointing because it is impossible for Bitcoin to just vanished like that.