Bitcoin will exist as long as there's one or at least few computers running a bitcoin full node. What could possibly stop this? Probably a global blackout or a huge EMP(electromagnetic pulse)[1] or something.
[1]
https://en.wikipedia.org/wiki/Electromagnetic_pulseSome powerful EMP or CMP, or any other dangerous shortcut can destroy much more then bitcoins, destruction will be everywhere, human lives can be lost, why would we care about bitcoin when there is more important things in life, or I am wrong?
This is 1003 topic about what can destroy bitcoin, and I always pay attention on this topics, I always see some new original answer that makes me laugh a lot.
Be interesting to see how crypto would cope with this. Theoretically, it is possible that all copies of the blockchain were destroyed, or that only one or two people were still able to run nodes. A lot of wallets would be destroyed and lost forever. Would crypto even be viable if it would take 10 years for global recovery? I feel people might have more important things to deal with.
Make a paper wallet and save your private keys on paper, in that way your bitcoins will be safe. After you will be able to recover your wallet, simple don't you think? That is a good reason to make one just in case if you are really afraid from some global blackout.