No, he's not right.
The chances of finding 'lost' Bitcoins is the same as finding 'wanted' bitcoins. As most bitcoins are 'wanted' you'll most likely just be stealing other peoples bitcoins. But wait a second? The chance of finding gold on the ocean floor is small but as we all know not absolutly impossible. The chances of 'finding' other peoples bitcoins are so many magnitudes more tiny that really it would be more truthful to just say its going to be impossible even if we had a computer for each molecule in the universe.
And dont get me started on 'lost' bit coins. Maybe I wrote down the private key in clay tablet that I absolutly expected would be dug up in 8000 years time!! You would never know!
You misunderstand. If SHA-256, RIPEMD-160, and ECDSA are never (as in not today, not next century, not 489230824390248390 years from now) compromised then your right lost vs not lost would be the exact same (essentially 0%) chance.
However the more plausible scenario is that RIPEMD-160, SHA-256, or ECDSA
will eventually be compromised and while it will be difficult to brute force (think mining but for existing coins) it will be possible. Long before that theoretical attack becomes useful a NEW bitcoin address type based on NEW stronger algorithms can be created. Over the course of years (potentially decades) coins would be moved to these new addresses. Given the increasing risk of losing ones coins it is very likely the only coins remaining in "version 1" addresses would be the ones which can't be moved because the private keys have been lost.
