I disagree that there is no such thing as a donation. I am sure in the years of 2008-2012 people who held Bitcoin may have had the idea that by destroying supply in some way, would positively contribute to the economics of Bitcoin due to reducing the supply. These actions would be considered donations to the network. It's very unlikely that this still happens with similar amounts. Maybe similar things happen today, though it just seems less likely due to value difference at that point until now.
Those who irresponsibly held their coins and then lost access to them did not voluntarily donate to the network like the above, rather their own actions and unfortunate circumstances led to an involuntary donation to the network, as their loss becomes beneficial to the economics of Bitcoin (again, less supply).
I agree that bruteforcing is unlikely to ever be successful and if it ever is near, a patch will be implemented prior to it being deployed against Bitcoin....I hope.
Those who irresponsibly held their coins and then lost access to them did not voluntarily donate to the network like the above, rather their own actions and unfortunate circumstances led to an involuntary donation to the network, as their loss becomes beneficial to the economics of Bitcoin (again, less supply).
I agree that bruteforcing is unlikely to ever be successful and if it ever is near, a patch will be implemented prior to it being deployed against Bitcoin....I hope.
There are also "dormant" Bitcoins which are kept in a cold storage wallet for later use. Some people believe these coins are lost because of the inactivity on the Blockchain. There's really no way to tell if Bitcoins are lost or dormant. But you can rest assured that BTC won't be affected just because some people lost their coins. There are plenty of satoshis for everyone to get into the game. The more coins lost, the higher the price of a Bitcoin will be.
Of course, cold storage is something I forgot to mention. Nice one!
I do wonder though, if you stored coins in 2008-2013, would you have just kept the private key and left it this entire time, or would you have moved the coins to better storage following? If someone is still holding their coins from that era and has not touched them, while keeping them safe and having peace of mind with the way they store it, they definitely deserve some credit and commendation.
I'd focus on buying and accumulating BTC to prepare myself for the future. Who knows if we're closer to $1m per coin than we've ever thought? Just my opinion 
For us that unfortunately don't have cold storage from that era, ecactly. The only thing we can do is focus on accumulating! Good luck everyone