With regards to IPFS, you'd need to find a pinning service that offers long-term contracts. Moreover, I have more confidence in the Internet Archive in being around in 10, 20, 30 years compared to any existing pinning service. That's not meant to be a slight against said pinning services, just that the IA is well established in their role.
They drop stuff that has the least amount of accessing, so if you want to keep something online you have to pay someone to keep accessing it. Makes sense, but I'd argue that it should be a market, meaning the price should go up as more people try to access stuff, but anyone can start to seed popular content and collect revenues also for hosting it (this is better than wasting electricity on accessing stuff or doing proof of work).
But isn't FileCoin exactly that for IPFS?
MaidSAFE goes a step further and has nodes rebalance autonomously and earn the most safecoin, as something gets more popular it gets seeded more.
