For example what do you actually call lost bitcoins? If some bitcoins are OP_Return command they are completely lost or say burnt and they can never be recovered and you can take out them from total supply so this is one case.
Now if someone has lost his coins through seed misplacement or say have not full 12 words then it's hard to brute force and crack the order of remaining words but if more words are missing then it's near to impossible to recover your coins.
Like some people don't find wallets with bitcoins in them and after years they find out wallet.dat file on the system and recover their coins so lost bitcoin for them were recovered but it depends on the actual scenario at that time.