In cryptocurrency, the block chain is only being used to secure the token and there is no purpose outside of that. The value is in how many tokens exist and what people are willing to pay for them.
I think you are displaying a misconception here. Most blockchains associated with cryptocurrencies at least ostensibly exist to provide some useful service, and the purpose of the coin is to provide an incentive for people to maintain the blockchain (i.e. mine/stake transactions). One example off the top of my head is Filecoin, which is supposed to make decentralized storage space available to users. The Filecoin blockchain does not exist just to secure the FIL coin - it's actually the other way around. The Filecoin blockchain records transactions (some amount of IPFS space for some amount of time, proven cryptographically somehow), and to make one of those transactions you need to pay with FIL.
Ethereum is another example. The blockchain tries to be a decentralized programmable computer (e.g. smart contracts, NFTs, DeFi). To use that computer, you need to spend ETH. As
@Walrus alluded to above, a high ETH price is actually somewhat counterproductive to the workings of the system, and the ethereum developers are working to try to fix that.
Bringing this back around to the thread topic, your statement
does describe
bitcoin. All that blockchain does is store a record of who owns the coins themselves, and nothing else. Some people say this makes it a reliable store of value, and some say it's a pointless waste.
You could argue, either cynically or accurately, that the
real purpose of any cryptocurrency is to make the tokens more valuable so that the originators get rich. Economists like the ones I quoted above would say that's fine and even necessary (and maybe even that it will lead to a new technology paradigm), while others say it's a ponzi scheme. I'm not actually trying to take much of a stance here, rather just laying out viewpoints that I don't see being discussed (and, to be honest, refine my own thoughts as I do so. So what if this isn't the most obvious forum to do it, I spend enough time here anyway).
Was this one of the questions, is the block chain only valuable when it is used for cryptocurrency?
Not quite. The questions I raise are 1.) whether a
decentralized blockchain is practically possible without a cryptocurrency (I think the answer is probably no), and 2.) whether a
centralized blockchain (without a cryptocurrency) has much to offer that existing technology (such as massively distributed databases like Google Spanner and cloud computing platforms like AWS) doesn't already do (to the point where people are talking about new computing paradigms). Here again I think the answer is no, but I'd be willing to be convinced otherwise. I could imagine that even if the technology is not actually better, it could be cheaper and easier to implement.
Note that I don't feel this second question is answered in the affirmative by the fact that some or even many people use this type of blockchain today. It would not be the first time a new technology is used because of hype (and the ability to sell it to customers), a point that was made in one of the links that I shared. And if you do believe its use alone proves its worth, then do you also feel that way about, say, ethereum, on top of which the entire decentralized finance system has been built?
