And by the final saturation point the value should be known well enough (and the other infrastructure aspects I mentioned will be in place) that lost coins will

And by the final saturation point the value should be known well enough (and the other infrastructure aspects I mentioned will be in place) that lost coins will be a negligible concern. An expansion of "exchanges" will help a lot as then you no longer have problems with abandoned wallets as the funds themselves can be used elsewhere until the owner decides to withdraw.