Lost coins only make everyone else's coins worth slightly more. Think of it as a donation to everyone.
Everyone, this is the post of satoshi from 2010, where satoshi said from the statement, where, yeah, it makes sense, it will be a donation to everyone somehow. Means the actual supply of Bitcoin of 21million will probably decrease.
This kind of nature in Bitcoin makes sense as that is how the power of no more Bitcoin will be generated, more than 21 million. And also the ability of everyone can create a Bitcoin wallet on their own without other entities, send and receive Bitcoin.