They are both wrong.

There are a small number of bitcoin which are provably lost, which means they are definitely lost forever and can never be recovered. This includes the original 50 BTC from the genesis block which cannot be spent, 100 BTC accidentally overwritten by a duplicate transaction bug, a few hundred BTC failed to be claimed by miners over hundreds of different blocks, and a few thousand BTC sent to provably unspent outputs (including, but not exclusively, OP_RETURN outputs). The total of all these provably lost coins is a few thousand bitcoin.

Anything beyond that is complete speculation. There is absolutely no proof that anywhere near 4 million are irretrievably lost. We see coins which haven't moved in >10 years suddenly "wake up" with some frequency. We have seen messages be signed from addresses holding long dormant coins, proving these coins are not lost at all. And even if all these early coins are lost, then quantum computing will likely make them accessible at some time in the future.