Is the blockchain an interesting innovation, aside from cryptocurrencies ?

My principle of "blockchain's fundamental value" is simply this: A blockchain that secures valuable information is valuable.

To break that down further:

• "Valuable information" isn't data - it's something that you can interpret, that has meaning and power to affect your actions. So, price speculation taking place on a chain isn't that valuable in a broad, utilitarian sense, but something like encyclopedic knowledge, historical records, and the like might be. The sense of "this is real" vs "this is Monopoly money" is related to the information quality.
• "Secures" means that we have some idea of where the information came from, who can access it, and whether it's been altered or tampered. Most blockchains follow the Bitcoin model and are fully public ledgers, storing everything - and just within that model(leaving aside Monero etc.) there are positive applications, but "automatically secure" is all dependent on what application you're aiming for.

You don't need to include tokens, trading, finance, or the specific method of security, to arrive at this idea of what a blockchain does, but having them involved addresses - though maybe without concretely solving - the question of paying upkeep costs, a problem that has always dogged open, distributed projects in the past. If the whole chain becomes more valuable because one person contributes something to it, then you have a positive feedback loop in which a culture of remixing and tipping is good. It tends to get undercut by "what if I made scam tokens and bribed an exchange to list them", the maxi- "we will rule the world" cultures of Bitcoin and Ethereum, or the cynical "VC-backed corporate blockchains", but the public alt chains that are a bit out of the spotlight with longer histories, stuff like Tezos and NEM/Symbol, tend to have a more visible sense of purpose in this direction - they need to make a myth about themselves, and the myth turns into information by chance and persistence.

What tends to break people's brains - both the maxis, and people who are rabidly anti-crypto - is that securing on-chain value in this way also isn't a case of "public" vs "private" goods. It's more akin to "commons" vs "enclosed" spaces, which is an older notion that hasn't been felt in our political lives in centuries, because the partnership of nation-states and capital has been so strong as a societal coordinating force - the state says where the capital should go, the people that follow that lead and build out an empire get rewarded. The commons is, in essence, the voice in the back of your mind asking, "Why are you in the rat race? Do you really need an empire?" And this technology is stating that, clearly and patiently: making a common space better is another way to live.

And so there is a huge amount of spam around "ownership", but ownership itself isn't really a factor. That's just another kind of information that the technology is geared towards storing. The social contract is more along the lines that if you are doing good for a chain and taking few risks, a modest, livable amount of credit is likely to flow to you in time. Everyone making "plays" and getting burned is trying to gamble with it, or to advance empire-building goals in a basically hostile environment that will patch you out of the flow of information.