Blockchain, the Solution for Almost Nothing

Would it, though? Google tells me that India has a population of around 1.4 billion people. Let's assume each person has one phone number, and each phone number requires one kilobyte of number-mobility-related data. Then the database would need to store 1.4 terabytes of information.

1.4 terabytes doesn't seem like an impossible amount of data to store. That fits on a consumer hard drive! Dell will sell you a single server with that much memory! Request volume doesn't seem like a huge issue either, since porting a phone number is something people do extremely rarely.

If you want to buy a 4chan pass, you'll find there is no option to pay in EUR or USD. Cryptocurrency only. Is this because 4chan is operating an illegal business? No. It's because they cannot process payments using the traditional means.

Controversial websites get financially censored all the time. Here are a few that come to mind: Kiwi Farms, Wikileaks, Backpage, 8chan, Bitchute, American Renaissance. I'm sure other commentators can chime in with more. Calling blockchains a solution to nothing is pretty offensive to the those who rely on it to pay their expenses without another realistic option.

Not to mention, anonymous cryptocurrencies such as Monero protect both the recipient -and- the sender from financial censorship. I wouldn't want to end up on a public list or have my bank account closed for donating to a controversial person or organization.

And Monero could not provide the excellent privacy that it does without a distributed ledger authenticated by proof of work. When a Monero user spends money, he randomly samples the blockchain until ten dummy transactions can be found and combined with his real transaction in a construct called a ring signature used to obscure the true sender. This only works because the user can secure his own copy of the blockchain. If he had to ask someone else for those dummy transactions, that someone else could use process of elimination to identify the authentic transaction in the user's ring signature.

If Iran, Venezuela, and North Korea can barely avoid sanctions what makes you think a blockchain network can avoid something similar?

1) ICO - a way to raise money in a distributed manner outside the traditional financial system (think Banks and VCs).

2) Defi - a way to borrow and lend (and much more) outside the traditional financial system. One example, Banks get as much as 16-20% return on your depoiste -- you might see 1% of that. Defi solves that by removing the Bank and you can capture all of that yield. You can lend literally with a click of a button and see returns with every mined block. Take the money back any time you want.

3) Governance - there is a big social benefit if we figure out all the edge cases and the correct implementation. Many benefits in voting, real-world governance, and open source (what to work on next, what gets funding).

4) Many many Comp. Sci. and Cryptology advances; see byzantine general problem, zero-knowledge proof, and many more. Just one example of a company doing lots of research: https://iohk.io/en/research/library/