Of course, the world has not yet seen a blockchain that has been battle-tested, that does not reward the maintainers in a native token. So there's that. What's the incentive?
Unless someone solves this problem in the realm of game theory, it is impossible. This is one of the absolute foundational pillars for the stability of bitcoin the removal of which would create a sort of 2 legged stool.
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Will there be a mass realization that blockchain without bitcoin is just a slow, shitty database? How long will this realization take?
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I wonder about that, too. Most crypto people I know from meat space think some "newer, better" coin will supersede bitcoin, yet most don't know how bitcoin or any of the alts actually work.
What they also don't get is that if bitcoin was replaced by something newer, more shiny (assuming such a thing would exist), then not only would bitcoin be pointless but also the new shiny coin, and every next shiny coin down the line.
It's either bitcoin, hooks into bitcoin, or it's a parasite sucking on bitcoins success.