not sure how this is going to affect the network and also are these BTC lost forever? Is there a way to resurect them?
BR
They always say there is 21m btc well not really and this is why. Maybe there is only 20m because so many got lost like this. Same thing happens with copper coins except decades later you can still find those.
No is the answer to your question, Ive never heard anyone reverse engineering the bitcoin out of a lost address. If that were possible it would make reverse charges and all sorts of things possible so I think its fairly simple to say once its gone then you would literally have to physically dig up the old hard disk.
Only other thing is if Jonny mnemonic had memorised the exact unique code for that btc address in his head, how long is that someone want to say? Then you can reconstruct.
I guess the other idea might be what if they forked and changed the rules somehow so coins can be recovered
The effect on the network is natural deflation. There is a tale of a popstar burning 2 million cash, same thing. The value isnt lost really, it was just paper. In effect value of these lost coins is now placed with those in distribution. Obviously hash codes by themselves might be unique but they are not of inate use so the value is transient. If your friend lost 1000 coins, he made a donation to every other btc holder.
The creator of btc was a smart guy and allegedly he has alot in a wallet? my guess is they'll never be used for this reason, maybe he removed all temptation or not; there was the case of an ancient Indian temple where they discovered hundreds of gold bars kept over centuries and amazingly never used by the temple priests