Bitcoin should not be treated as a physical asset. With a physical asset, if someone else possesses it then you do not. If you lose cash, a credit card, your wallet, your phone, or any other physical asset, then it is obvious to you that that thing has been lost as it is no longer in your possession. Losing a private key is not the same, since it is entirely possible for two people to both possess the same private key at the same time. A better analogy in this case (ignoring the whole self-custody aspect) would be like someone having a key to your safe, or access to your bank account. If I look at the contents of your safe, and then 5 years later see the same contents in that safe, do I get to take them for myself since you haven't used them in 5 years? If I have access to your savings account with $10k in it, and 5 years later is still has $10k in it (plus interest), is it morally fine for me to clear out your account since you haven't used that money in 5 years? Of course not. Bitcoin is no different.

Coins not moving does not equal coins lost. It is nonsense to suggest otherwise.