Stop thinking of bitcoin, ethereum etc as currencies for a second. Think of them as databases that can not be tampered with by anyone. Not by the people in charge of managing the database (no one is), not by hackers, not even by governments.
What you use that database for, is entirely open. Basically anything that represents value or rights or requires trust. From car maintenance and ownership records, to real estate, intellectual property rights for anything from photos to patents, company shares, contracts,.. It has the potential to replace the trust that now requires countless companies, institutions, government regulations, mandates and licenses, who's sole purpose to exist is minimizing the risk of someone tampering with the databases that currently store these records. DMV, patent offices, stock exchanges, notaries, and yes, maybe even (central) banks. Thinking that has no value is delusional.
And before you say "Blockchain but not bitcoin", you can not have a trustless blockchain without a native asset. Blockchain without it own token is bullshit, thats simply a fancy slow database that still requires third party trust.