In reality you're right, I was speaking in hypothetical of "on a long enough timeframe" which could be thousands of years.

I dont know if I agree. If I make a key and use it to generate addresses at which I receive some btc and then I accidentally destroy my backups, the only way to recover the btc would be to crack the locking script. If that happens, doesn't that imply that all bitcoin locking scripts are crackable? If we can recover lost btc it implies we can crack any bitcoin private key. 

Scoresby

But they also could be recovered on a long enough time frame

030a29f333

bitcoin_beginners

Question on the 17.6% lost BTC

alashazam

Something I often think about is that the amount of btc that is lost (meaning the keys unlocking a specific utxo have been deleted or destroyed in some way) only increases and so I would think on a long enough time frame all btc will eventually be lost.