Ok, list some legitimate uses of bitcoin that actually exist in the wild outside of speculation and doing something once for the novelty of it that would require a bitcoin ATM in a gas station in Texas. There's four stories: speculation, money laundering, black market drugs, and "one time in 2012 I bought a pizza and that money would have bought me a mansion today".
>Are you saying the gas station owner has some liability?
Sometimes, yes, helping create a situation makes you partially liable even if the individual pieces of what you're doing are legal.
Having full ownership over your money in digital form has quite a lot of disadvantages, so many disadvantages that it makes it a bad idea to do it in general. However, there are a few advantages under certain circumstances. You can easily wire money-equivalent into a country where banks are closed. It also forces countries to be a bit more cautious with acute money regulations in times of crisis (because Bitcoin is a tool to circumvent those).
I do however agree with your post on general. Bitcoin (and all other crypto currencies) is used for money laundering, speculation, doing things that would be illegal with properly regulated assets and for buying illegal things like drugs.
It's been around for quite some time, if there were more use cases we would already know by now. There has also been no substantial development since Etherium "let's make it turing complete because what could go wrong lol" and the world pretty much agreed that it's a bad idea to couple money transfer logic to publicly available code while a bug can make you lose all your money connected to that logic.
It's not like it wouldn't be possible in general. But nobody cares and obviously nobody sees how serious development would lead to anything useful (very few counter-examples like the people that created Monero).
Blockchain tech _is_ useful though, but mostly not to consumers unless they're trying to circumvent the law.
Private blockchains between semi-trusted entities that need to keep accounts between them are great. It really is just a shared ledger, a shared database with the mechanics for keeping accounts in a way that's mathematically trusted so no one party has to own the ledger. This is good for banks settling accounts between each other which they very have to do nightly for a variety of reasons.
Are you saying the gas station owner has some liability?