If you have a flash drive full of bitcoins and then suddenly, you lose it or it became unusable, the bitcoins in there will be gone forever. Am I right? So, if that's the issue, is it possibe that we run out of supply of bitcoins? If that were to happen, will bitcoin die along with other coins? Or will it die alone?
If you have lose access to your wallet because of the device you use is not usable anymore, those Bitcoins that are stored in your wallet will not be gone, it is just that you can't access it anymore (unless you wrote your private key on piece of paper or somewhere, you can still recover it) but it is still in the Bitcoin network. If all people are stupid enough to lose access to their Bitcoin wallets then it is possible that we will have a shortage in supply in circulation, but that is a very unlikely scenario, not all people are stupid so don't ever think about this again.