Bitcoin as a currency doesn't solve any problems for people in developed countries. For the 5 billion plus who are underbanked due to lack of access or government red tape, it solves a big problem. Maybe you live in a country where there is hyper inflation like Venezuela or Argentina, or you are a female in Saudi Arabia and you cannot open a bank account, or you need to purchase prescription drugs online because you cannot afford it. Bitcoin is not perfect, but it actually solves problems for some people. We mostly buy Bitcoin in the west as speculation.

I think the real value of crypto will come when the market is stable enough that people feel comfortable leaving their money in crypto instead of cashing out (avoid the commissions). Get paid in crypto, buy goods and services in crypto, and never have to deal with cash or banks. I think a great use for crypto is microtransactions which are cumbersome using cash (literally coins) or expensive using credit ($0.30 transaction fee).

Sadly transaction costs in established crypto are quite high for small (<$10)transactions. Microtransactions are not viable at the moment.

There would have to be a solid(likely with some sort of central authority) proof of stake crypto for inexpensive microtransaction models to work.

Of course the alternative is doing it off chain but that pretty much gets us back to trusting some sort of central authority.

You are paying for privacy. There is no company to sell your buying habits. There is no company the government can demand turn over your purchasing history.

This all depends on where you are. In the US, you have to provide KYC information to get bitcoins so there will be a wallet tied to your personal identity. From there, you can follow the transactions on the blockchain and see where it leads. It isn't as easy as a subpoena to get information from a single company but it isn't like there is actual privacy either.

Not counting Monero and a few others, most cryptocurrencies are only pseudo-anonymous.