I've been doing more reading lately about the topic of "digital preservation" and one topic that comes up is how in any long running digital system, there is not point of "having preserved digital content", instead it's an endless task of "continuing to preserve" digital artifacts.

In the same way, I don't think you can say Bitcoin will ever "be a success". Rather, I'd say that it's "currently successful".

How can we ensure bitcoin's continued success?

Not to shill Base58 but to totally shill, I really think that if we're not taking the time to build good information about how bitcoin works, the protocols that it's built on, and making them really easy to access and find information about how the protocol works, we risk atrophying as an ecosystem over the next 10, 20, 50 years. It's important to me that people are able to really understand bitcoin, because without that understanding you lose some capacity to stay self-sovereign and decentralized.

I think all the work every bitcoin educator is doing of teaching people how to hold their own coins, how to run a node, how to look at mempool.space and understand what they're seeing -- this is all really important for bitcoin's continued success. :)