Not all coins that haven't been moved for years are lost forever
Some are just holding or temporary have no access to their wallet and this are usually branded as lost.
The number of lost coin are estimated not fully known
So even if Bitcoin protocol could enable such (the community ain't foolish to do such ) it would be nigh impossible to get the right number to add.

If the supply of Bitcoin could be easily altered then what differentiate it from shit coins.
It's limited supply plays a central part in it's value.
Lost Bitcoin despite the pains it would cause would increase the value of Bitcoin as goes on
And unfortunately more coins would be lost within the mining years of Bitcoin.

Lost Bitcoin can still be found if the private key lost or wallet password was found.


Even in the case of Fiat.  If you lost your money at your personal disposal the government ain't compensating you
This also applies with Bitcoin
I see no reason for compensation for something they have no fault in.