How is this different from cash?
It's just that in the case of btc, there's no central authority to cancel the transaction. You need a court order to force the bar to manually send the money back to you. The bank cannot freeze the funds. Enforcement is crippled. If this is not a reputable business (unlikely for a bar and very unlikely for a small sum like that but bear with me), it's way more likely to lose your money.
This is one of the reasons why money transactions are hard and costly. You cannot pretend that a blockchain fixes all that.
If I lose 50 € to some unscrupulous merchant, that's worth it to not have to ask the bank for permission for and tell them about every transaction.
in other words, you aren't poor enough for the loss of 50 € to mean that you are going to have less food this month and won't be late on your rent because of it.
But poor people do use banking services and in both countries I've lived in (US and Norway), there are built in consumer protections. They aren't perfect, but they are stronger than you get with crypto. You can often resolve a payment issue, for example. FDIC protection in the US covers most folks (most folks don't save more than whatever the limit is now).
And this protection, even if imperfect, helps folks have a little more stability in their lives.
To the extent that the risk profile is or will become (with expanding regulations) the same as with cash, cryptocurrencies provide no meaningful improvement over cash, but have significant drawbacks.
So why should we take all this effort to get to "just like cash, but with extra steps"?
In this world however, disputed transactions may even be more than half, depending on the industry. You can't approach something that ignores this as a serious financial tool.
Compare a frozen bank account to a fraudulent transaction you can't revert. Sure, the latter is more frequent, but the former is devastating.
That's a feature, not a bug.