I disagree, the guarantee is the technological innovation Bitcoin represents. Solving the Byzantine General's problem with a decentralized public ledger was a massive advancement in computer science. It cannot be ignored.
It's folly to pretend things are the same now as the were before this technology existed. They're not, and they never will be again.
It is true the progress brought by the underlining technology behind bitcoin can't be denied and in many ways it is revolutionary.Its potential does not solely lies within just cryptocurrency. That of course does not guarantee bitcoin's mass adoption,as I stated earlier the general public would only care if it more accessible to them and there is enough perceived benefits to warrant the effort and cost .
They are plenty of tales of cool technology that never lives up to their hype(usually by being overtaken by something else).
The examples that I gave(PDA and pagers) never did capture the public imagination much regardless of how good it was at its intended utility and quickly falls to the sideline the moment cellphone catched up(and bypass them thanks to the advent of smartphones).While they did not go the way of the rotary phones ,both this technology now only served some very niche application (a far cry from the brouhaha of their zenith).The same can happen to bitcoin .
Regardless of ultimate its outcome , bitccoin is definitely a landmark in its own right and I'm sure future archivers note how significant it was(while us that lives through it reminiscence about it).