Assume that some fund hasn't been moved for years. How can you know that whether the owner has lost access to the fund or the owner has decided to hodl the fund?
Here is the idea of bitcoin creater about lost bitcoins.
Lost coins only make everyone else's coins worth slightly more. Think of it as a donation to everyone.
No Bitcoin is lost on the network, only people lost the way to access due to many reasons.
I don't agree with OP, but there are coins that have been provably lost.
OP-return outputs are lost. Some coins were lost due to miners not claiming the block reward and there were also coins that were lost due to the coinbase transactions having the same hashes.